I'm running everything I need and I don't even use the Google Play Services compatibility layer app.
Having said that, even if you install those Google apps on GrapheneOS, they don't have more privileges than any other app, so you can just revoke access to whatever you want, and it behaves.
On a normal phone Google can do anything to everything without you knowing.
I recently switched to GrapheneOS from iOS, since I was getting pretty tired of Apple's privacy LARP. In general, it's been such a huge downgrade for me, but I'm willing to stick with it to give it a fair shake. The thing that bugs me the most is just how many apps (especially ones I consider essential, things like Lyft) require google play services. At the very least, they can be sandboxed, but I'm finding myself significantly more googled than when I started
When you don't have Google Play services, correct me if i am wrong, but you lose Firebase, thus the ability to receive push notifications from apps like WhatsApp. I think Signal has an always on background service running, always listening on notifications, but that is much more battery heavy and additionally, creates more load on their servers. Also many other apps entirely rely on Firebase for push notifications.
You'll be surprised to find out that some of us interact with 'normies'. We have family and friends who don't have the time, money, or attention to get a new phone that can run an alternative OS, install a 'perfectly secure' messaging system. Whatsapp and signal are pretty good. People are already using them, it's easy to share photos etc.
I think given your description, Android is right. If it were just certain countries, the results likely vary. I’m sure someone has published statistics on it.
In 2009 it was all just Windows(maybe that's why Satoshi released Bitcoin as Windows only in genesis), then somewhere around 2017-2018 Android took over for the first time, and in the last couple of years it separated even more as the most popular OS worldwide.