Depending on how abusive you are thinking, that sounds like rubber hose cryptanalysis. That's a hugely powerful approach and I think all 2FA can be bypassed with that, if not most of modern cryptography.
Keep in mind that other 2FA methods also are phone based, like TOTP / Google Authenticator. Those also fail if your unlocked phone is taken. SMS is even weaker than those, but still better as a second factor versus nothing.
Depending on how abusive you are thinking, that sounds like rubber hose cryptanalysis. That's a hugely powerful approach and I think all 2FA can be bypassed with that, if not most of modern cryptography.
https://en.m.wikipedia.org/wiki/Rubber-hose_cryptanalysis
> having their phone taken
Keep in mind that other 2FA methods also are phone based, like TOTP / Google Authenticator. Those also fail if your unlocked phone is taken. SMS is even weaker than those, but still better as a second factor versus nothing.