For me it’s Whatsapp. Like 99% of people i know use it so yeh… i still need it. I am considering moving the Whatsapp Gdrive backup to a local backup btw.
Google photos is also a major problem for us. We have a lot of stuff that want to migrate to different service (or store locally).
14 years on Linux, 2 years with a graphene phone, no google play apps at all.
Replacing Gmail with posteo.com took the longest, adjusting everything per website, and testing, One drive has been replaced by https://filen.io/
A happy user again with control of everything.