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There are few exchanges that allow users to create account using their mobile phone numbers, compare to using email account I think phone numbers has more risk than email account, if you are a newbie and you want to create an account on a exchange please use an email address instead.

You can easily create a new email account and use it for exchange registration, unlike phone numbers that has access to your security number and bank account, if anyone get access to your number either through hacks like SIM swap you will lose more than your crypto assets, your money in the bank isn't safe either.

Your security number can be used for other criminal activities too, my advice is to keep your mobile phone numbers out of crypto things.

You are right and it's good to bring this in newbies' attention now and then, however I would extend this by recommending a good read of Why KYC is extremely dangerous – and useless (https://bitcointalk.org/index.php?topic=5221497.0). It doesn't cover the phone, still it's an eye opener for being much more careful on what data we give out to unknown people and businesses.

I will add that even e-mail can be tricky and could be good to use only one e-mail (or set of e-mails) only for crypto related stuff.. because even changing e-mail can be a problem (eg. giving up an e-mail all your friends know).

Probably using both email+phone numbers is the more secure way for those exchange accounts.

About using a new email, specify for registration on exchanges, I used to have a problem with forgetting my password. because such email addresses are rarely used, and it should be avoided that the browser saves the password.

For a change, I started using personalized email addresses from domains that are owned by me. for example something@myowndomain.com. In that way, I don't have a problem with lost passwords, hacked email addresses, or restricted access.
as long as I manage the domain, which in that case is hierarchically higher, I have no problem accessing any email address. I can also create a separate address for each service if I suspect phishing or something similar.

Using email is a much better option and you can easily create almost unlimited amount of normal and temporary emails, but problem is that some exchanges and services are asking for mandatory phone numbers.
If you must use phone numbers than you can try using temporary voip numbers or buy prepaid cards without connection with your real identity.
Note that Bisq exchange wont ask you for email, home address, passport or your phone number ;)

I use a password manager (Bitwarden) to avoid exactly this kind of problems. It's close to "browser saving password" as usability, but it's not in the browser, hence imho safer.

Plus, instead of having new e-mail for each new service, I have a list of e-mails I use for "not so important" things.
I will add that certain e-mail providers (eg. gmx.com) offer a number of alias addresses so you don't even need so many accounts, and in case of problems you dispose the problematic alias.

You're talking about centralized exchanges since it's need a phone number to create an account, if you're using decentralized exchange e.g. Bisq you wouldn't need to create an account and expose your personal information.

Phone number can get attacked by Sim swap, but email address doesn't always the most safest way if you're also using phone number to recover your account. You can use privacy oriented email providers e.g. protonmail or tutanota since it doesn't need phone number. 2FA could add extra security, but it's useless if your phone get hacked.

I don't remember signed up for any cryptocurrency exchange with my mobile number but every time I used the email but it doesn't mean you can feel safer and also it is not advisable to use new email for everytime you register on a crypto related platform.

If you feel you don't want to expose your primary email then keep a secondary email for every crypto related stuffs and when talking about exchanges never forget to avail the 2FA authentication security feature which can save you from phishing and swim swap attacks.

Exchange usually has multiple type of security that can be setup on an account such as sms, email and 2FA verification. It’s really dangerous to use mobile phone number only to create an account without any other security but this will be helpful if you setup multiple security since you can be easily notified if something is wrong with your account.

In my case, I’m depositing significant amount of money on my exchange so I use personal email and sms to create my account since it will be painful in case I use only a dummy email or sms and somehow I lost access on it since I’m not using it most of the time. I still preferred my personal sms to give me quick update since I’m not viewing email very often. But of course I’m just doing this on website that I can trust not and not to those mediocre services.

Both phone number and email have risk.

Some email providers require phone number when you register your email. With phone number, there is Sim Port Attack (https://bitcointalk.org/index.php?topic=5146701.0)

With email, you must turn on 2FA that has two options (SMS code and 2FA application). You should not choose SMS code because sometimes you will have issue to receive SMS code. Reasons can be from telecommunication company or newly applied restrictions in your country.

With 2FA application, you are free from government and it is how we survive in crypto.

When you use 2FA, make sure you backup its code for recovery if your initial device is technically broken.

Indeed, the phone number is one of the targets of hackers, some crypto exchanges have a phone number requirement. One of the things that is required, for example: the exchange I use is 2FA, phone number and email, needful.

My country has a rule for its citizens to use a phone number of no more than three registered phone numbers/one citizen, which is for sure at this time the phone number that I use is only for crypto exchanges, The second and third phone numbers are free for me to use, but for now there are no suspicious signs, for that the phone number I use for the crypto exchange, the phone number is not used for others, only for exchanges, it's regardless of risk.

Would it already be a problem we can encounter if you provided cell phone numbers to someone? I’m asking this. Because there have been a lot of scam texts in my country that annoy me, and if they know my number, would it be a problem? I don’t see how they would be able to use or hack a Sim by just knowing your number. It would be a problem for everyone who has been compromised to know their numbers and names.

It depends on how you will keep safe with your devices at the same time is phone numbers are likely public and easily can bought into different market there's no safe in the internet today if you have different number it is good to have it instead to make sure your funds is safe. Currently im my country not yet implemented the use of single number for each person so they can easily change it. And still the same with the safety of the email too, but it is more secure because of another layer security.  The best way is get a 2FA and KYC to make sure you are easier to get back and track your funds.

It's really very unsecured to use personal phone numbers to create any crypto related account. We should use it for 2fa activation not for creating an account. It's far better using emails to create any crypto account than using phone number. I always use my emails when creating an account on any new project.

In addition to everything that has been added above, I would also very much like to caution everyone not to publish their mobile phone number, for any other purpose, on the Internet. My number was exposed by someone in a telegram, after which I received a catastrophic amount of spam, not only in the telegram but also in the form of promotional calls and SMS messages. After that, I had to change the number and use separate numbers for both calls and instant messengers.

Is there any crypto platform that forces users to oblige to add their phone numbers? Most of the platforms I used give the phone number option as an additional option to enhance privacy, but they do not force the user to add it.

I do not recommend such services, as most of them resell the numbers every X months to a year.
and Renting a real number costs about $2-5 per month.

Besides what you mention, I know of some crypto related services that, at first, accepted the usage of a virtual number, but later on detected that they were such, and blacklisted the number. They claimed that, despite it no being mentioned anywhere in their TOS, they required numbers that were related to non-virtual phone service providers.

Prepaid cards could be an option, although the need or exemption of a registration with a KYC procedure will depend on the country as can be seen here:
https://www.comparitech.com/blog/vpn-privacy/sim-card-registration-laws/
https://prepaid-data-sim-card.fandom.com/wiki/Registration_Policies_Per_Country

You can get around this instead of providing a centralized exchange of your primary cell phone number. I registered an account on a centralized exchange and they asked me to add a mobile number as part of account and fund security besides they also asked me to pass KYC.

In this case I am not using my primary mobile number, but I can buy another mobile number freely for this purpose. Others, I also don't use android to receive message verification, that phone number is specifically for me to use on GSM phones. So far so good, but I'm not 100% sure this way is safe in the long term especially about my personal data on that centralized exchange.

It will be harder for hackers to have access to your email account and your phone number at the same time, pretty hard, that's why using email is most recommend and yes one can use mobile phone number to receive verification codes and this is safer than using your phone number only, the combination of the two is safer.

We have to combine email and cellphone numbers to increase the security of the exchange account, but it is recommended to still add google auth security as a priority for security. However, we must have another personal mobile number that is used specifically for code verification purposes from the exchange.

If you have access to burner numbers then it might be a good idea to use them first if you're trying a new exchange. Some exchanges sell their user data to another party, and risking your main phone number might not be a good idea. Even if you prepare a specific number, if you already KYC'ed there, it won't really make a difference.

The combination of Email address, Phone number and Google authentication is secured enough when you open an account on any exchange, this way it will be tough for anyone to have easy access, still its left for the exchange team to get serious with their security this is why leaving your assets on any exchange is highly risky, do not try it.

It's still not enough. Some exchange offer alternative login in case you forgot one of those as long as you have the email address of the account since you can request to turn off the security by just verifying your action on email. Binance doesn't allowed this but some mid tier exchange has this kind of feature which is very risky for user once they exposed there email to the hacker.

Not only crypto but any other thing you want to use your phone number for registration. Many registrations demand the use of a phone number, however if using an email address is an option, it should be chosen over using a phone number.

I recall receiving a call lately from some scammers who had registered a new WhatsApp account using my phone number and asked me to provide a code that they would give me while we spoke. They accurately identified the organization I am a member of when they mentioned there would be an online meeting, and that I would need to provide them with that code in order to participate.

I was given the code, but all I did was ask them a question that they were unable to answer, and as they realized I had identified them, they hung up. I'm affirmative they obtained my number during an earlier registration process in which I used my phone number. They were able to compromise the information there and are now searching for victims to fall into their trap.