I think Sign in with Apple is a great step forward even if all it does is eliminate apps that require Facebook and/or Google accounts to log in. I hate that - I actually ran into a feature on my mesh router system that required a FB/G login, which made it a useless feature for me. Fortunately I didn't need it..
1) Identity is an email address. If I wanted to rip out Google, or Google kicked me off the platform, all I need to do is add passwords and put a "forgot my password" link and my customers continue business as usual.
2) It's not a google-specific email address. You can create Google accounts for any email address.
3) Google login effectively lets other businesses federate their auth system with ours. When they terminate their ex-employee's @example.com account, the employee loses access to their resources at my company.
I don't think you could get away with this for a consumer company; too many people have strong feelings about FB/G/Apple/whatever. But it's fantastic for B2B.
It's a choice they made, nothing specific to Google or OAuth.
There may be other options if you want to mess with oauth yourself, but this one is pretty near zero effort.
Mobile number login is even worse! Why do I need to share my mobile number for something where you don't need to have it!
I think you got this the wrong way around.
Their whole point was that you could be confident the people were real because they were tied to a real Facebook account.
This was the first month of Pokemon Go years ago. I haven't heard of it being an issue lately but I also haven't needed to create an account in a very long time.
And a bit over a year the same thing happened. New Pokemon Go account -> log in -> no game. With Google account has been working since.
So, my experience is two tries in the span of two years it did not work.
I’ve gotten rid of Facebook, but now my account name is just a bunch of numbers.
Also there are cases where a "sign in with <particular provider>" is the only option that makes sense because you really want to integrate with the API of this provider. Take for example a "sign in with GitHub". Or in case of services correlated, take for example Instagram where you obviously can sign up with a Facebook account.
I'm more for letting the developer choose what it prefers for authenticating the user and not having a authentication system that gets imposed by Apple.