I personally am fine with this.
And not the twitch way, where you have to have in an identifier, your phone number, but using proper, standards ways for it, like TOTP and such
As the other commenter said, only if you give them your phone number, and only through that garbage authy that does not use standard TOTP, but some proprietary crap, specifically made for twitch.
And if you give them a phone number, which another user will also try to use in the future, then the secret used for TOTP can change in any moment, which means if you exported the secret to e.g. Aegis and deleted that tracking filled garbage that is named authy, at one point the codes just won’t work anymore, and you’re practically locked out. Apparently support should be able to help, but they don’t give a single fuck.
and only through that garbage authy
you can use any TOTP app. I use bitwarden
true. But I think that’s mostly to make bots harder to create. Not as easy to get a phone number than an email address