I have used binance for a long time and you can't login with just your phone number, the reason why is because you have already verified your account and your email has also been verified, your phone number has been verified too, so even if you try to login with your phone number you still need to have access to your email account because you will also be asked to verify your email address...
Na d koko be dat, except dem don change am yesterday. No exchange wan make am easy for hackers to break in and steal funds but sometimes their security measures too dey affect real owners, especially wen we misplace awa login details or access. As far as d email don dey verified, Binance go wan dey sure who dey enta dem site by still sending OTP to d registered email even if persin use phone numba take sign in.
Na dis similar issue I dey battle wit for MexC now. My own case be sey I get access to d exchange but I nor fit transact there as I nor get access to d Google Authenticator wey I used tie my account unto 2FA. Even wen I supplied my email as an alternative authenticator, MexC go send OTP to my email and still send to my GA. Dat's, I must use both OTPs. If not, no access. So, I've been locked out of doing any transactions there for now.