It is absolutely not a no-brainer to use Google/etc accounts instead of handling that oneself. The last thing we need is an Internet which is unusable to anyone who chooses not to have (or gets banned by) big tech companies. I myself refuse to use the federated login option because I value the ability to not tie my entire life to my Google account.
I'm pretty sure you didn't have the "for most users" qualification when I first replied. I may be mistaken, but I don't remember seeing it at any rate.
there are plenty of options for 2 factor apps that don't require login. in fact, even Google's authenticator app does not require you to login. you can use it locally and store the codes locally.
