What still requires stock Android and has no alternative way to access?
I'm about to degoogle my stock Android phone. For the past few years, I've used it to handle the non-open source apps that I don't want running on my main phone. As I've finally weaned off GApps, I realize that I might as well go degoogle the rom as well.
edit: to be clear, I'll be using sandboxed Play services on GOS
But since that phone is my compatibility guinea pig, is it likely I'll still run into an app that demands unmodded Android with no alternatives? In your experience, has any bank or other service required the app on regular Android, with no alternative for the desktop, browser, etc?
Yeah, only thing I can think of is the few banking apps that don't have web versions.
I was lucky enough to have all my banking and 2FA apps work perfectly on GrapheneOS. The only app that gave me a significant amount of trouble was iClicker, which my school uses for attendance. That was fixed by enabling Google Play location services, and there was a (fairly expensive) alternative anyway.
I did have to buy a new phone to use Graphene, because I got my previous one as part of a carrier's cell plan, and it had a locked BIOS. Though I think the purchase was worth it, and just moving my SIM card from one device to another was enough to get it working.
NFC payments with Google wallet, in theory if your bank provides the service in their app, you could still use this kind of payment, haven't tried it tho.
Also I only found a developer for which their games don't work, it's the developer of guardian tales.
Aside from that, with sandboxed play services there hasn't been any difference since I migrated to GOS.
Authy 2fa doesn't work on GOS because of Play Integrity. GOS has been talking with regulators in the EU about this.
An Amazon delivery locker doesn't open without Sandboxed Google Play installed, I've switched to post office deliveries. I had to change my account user name to my actual name ( my name is extremely common so no big deal really) but at least I don't have Amazon's shit app installed anymore.