They literally bought a third party app that they rebranded as the official one. Reddit only has an app because of third party apps.
Yeah, they're not pushing it because it matches some far-right authoritarian ideology Meta itself has, they're pushing it because conservatives taunting libs who fall for it and try to talk reason into conservatives drives tons of engagement.
It still defends against one failure mode (the website gets hacked but you're ok) but yeah, obviously if you get hacked and the hacker knows how to get your vault out then you're 100% screwed.
My suggestion is always hardware 2FA, even though it's not as mature as the other systems. Personally I have two Yubikeys (in case one breaks/gets lost) but it does mean that I need to add TOTPs to both of them each time I add a new 2FA.
It gets harder when you realize that an awful lot of conservatives (well, in the US at least) literally tie their personality to being bigoted. They simply can't not say offensive things. Even if it's completely irrelevant, they gotta slide something in somehow.
(Then again, as Mastodon has shown, there's the tenderfolk on the other side, but at least they're a pretty small group and don't make too much noise overall.)
$70 is typical for that, except it's 30GB of data for the month before they reduce you to around 25kB/s.