3Fa would certainly change things.
I don't think so.
Most people are lazy as f**k. They would probably use 1 device (e.g. their mobile) for the 2nd and 3rd factor, therefore basically creating a 2FA again.
If done properly, it definitely increases the security. But i doubt the majority will be able to handle this correctly.
What? All this time I thought that activating 2fa on all my accounts made me feel that my funds are very secured but now it is vulnerable?
It is not vulnerable.
But if you don't know how to protect your sensitive information... it is only your fault.
It's like saying "I thoughts passwords are secure, now my account is at risk if i tell everyone my password ?".
If you keep your 2FA codes secure, so that noone except for you can access them, it is safe.
If you share your 2FA codes (or they can be accessed by other in any other way), it is not.