In most cases a true second factor isn't really what any involved party cares about.
My bank (I mean, they use SMS, but pretend they use TOTP) just care about not having to spend money on support because I used "password1!" as my password for every account and lose all my money.
I just want to log in to my bank.
If I've got a long, random, unique, securely-stored password, I don't actually care about having a second factor, I'm just enabling TOTP so that I don't have to copy/paste codes from my email or phone.