If I'm using an app I'm very skeptical of "Login with Google" because I have no way to verify that you're only getting a random identifier and not my email address. I prefer to sign up with a proxy email address.
At least with "Sign in with Apple" you can choose to give a random alias that forwards to your email. I do this for every single service I sign up for. Completely unique Email + password for everything.
It's built into Android/iOS and an accepted way of logging into an app. The app store page (when it's released) shows exactly what I need: practically no information at all.
Google handle the payment and the subscription too (same with Apple) and that's a very common pattern too.