@_act_, you don't necessarily have to have a crypto wallet in which you keep a coin on your smartphone, but a smartphone can be a vector of attack on the crypto exchange you use while trading on the go. Whether it's getting a phishing link via text message or email, or someone will try a SIM swap to access your crypto exchange account.
In short, it is not recommended to trade via smartphones and various official apps or use SMS 2FA - there are many cases where it turned out to be a fatal mistake. How easy was (or at least it was 2020) to make a SIM swap in the US ->
https://www.usenix.org/system/files/soups2020-lee.pdfI too think computer (PC) is better than phone but because people do not carry it about like phones, like I have said before too, most of my online activities is mostly through phone which still make it more vulnerable to attack, but if using computer, some people have their email on the computer active and phishing link can be sent to the email. If some people do not know how to avoid phishing messages, it can be sent to their phone, transfer the link to their computer to proceed. What is most necessary about phishing attempts is for someone to know about it and avoid it completely.
I agree with sim authentication, it is risky and have led to scam in the past, the two that are most recommended are 2fa app and hardware authenticator, but having the 2fa app on the same device you have the account you are using it for is not also good.
With Google Play, malware and spyware is even easier to install. It is easy to create a developer account and publish a fake Bitcoin Wallet on the store. Check out Free Wallet. They have been scamming for years and they are still up and running.
Freewallet? Just that it is a custodial wallet and not good to use custododial wallet, using noncustododial wallet is good to have control on your coins.
There are many fake apps on app stores, they will be noticed, removed and another one will be there again, that is true. If downloaded, that is another scam again.
If the wallet is fake which is common on app stores, malware will be included to steal the coins. But it may be in a way only addresses would be seen as the developer will have the private keys with them.
Moreover. If spyware is a thing you are afraid of. It is worth noting an iOS or Android phone will have so much more spyware than a PC with Linux on it would.
That is true, you are right but most people are using Windows, an OS that hackers also prefer to design malware for to scam multitudes. Linux is not also completely safe, just that people that are using it are not many and used more by people that know how to avoid malware, hackers prefer just not to design malware for it, just little malware are for Linux.