If it is of a specific brand that enables encryption of data by allowing us to put up a password before any of the data of that USB be used, and the password is an extremely complex one, will it still be possible for someone getting my USB to crack that password and/or encryption and take away all the data in that USB?
It depends. Is it open source software that uses a tried and true method of encryption, or does it use a proprietary algorithm?
Keep in mind that a USB is also inconvenient. If you're using a non personal computer and needed to access your accounts, you likely wouldn't be able to connect the USB to your phone to find your passwords. Most password managers have apps that you can use.
For me, being able to sync my passwords with my phone and computer is very important. Additionally, if you manage your passwords in a Notepad or USd or whatever, you are not going to be able to generate new passwords for every website.
The main problem of repeating passwords through websites is that if one website is hacked and passwords leaked, your other accounts may also be compromised.
This is why password managers are good, because they can generate good and unique passwords with a single click.
For years I have used Firefox password manager, but it lacks this feature. Therefore, I am now moving to Bitwarden (the best option for me, because I need my passwords on the cloud).
I read somewhere something very interesting: The only password that you should know is the password of your password manager. All others should be automatically generated. To prevent losing more than one account if a service is hacked.