If you built up a Linux system to have similar functionality (single user account across systems that syncs user data, automatically backs up to a cloud, syncs photos and videos, sends all traffic through an anonymizing relay, receives push notifications for essentially all apps, etc), would it contact fewer services?
To some extent. You could do a lot of the syncing with a decentralized system like syncthing. You could use GPS for time.
Tor for anonymization and additional firewall-punching.
GPS isn’t great indoors. Tor just stuffs things through a tunnel. You could do the same on a Mac with a VPN and say it’s just connecting to one service.
And by the time you get to nightly backups and photo sharing across computers, I think it’d be pretty similar.
Given the state of modern tech enthusiasts? The answer for many is likely no, no they have not.
I've tried to use it as my daily driver multiple times since 1997 but ultimately for me personally and the security posture I have chosen to adopt the utility of being able to copy and paste from my phone to my desktop without having to deploy and secure my own infrastructure outweighs any paranoiac doomsday delusions someone may try to implant in my mind.
Have you tried using KDE Connect? It is really impressive.