I've just been reading up. Sounds like I need to do more research on G.OS in general in order to make an informed decision on the benefits and drawbacks for my case so I will be doing that over the coming weeks.
In general though I don't really use that much on my P3. WhatsApp, Banking, Gmail, Photos, Bitwarden, Authy, Evernote, The odd game or two, A few other apps that I occasionally use, and a significant number that I never use and probably should have already uninstalled! Oh and I do use the call screening, but none of the other things you mentioned.
I'm more inclined to go without than to jeapordise my privacy (paranoid I guess) even though I'm probably already massively exposed hence why I thought about giving G.OS a whirl.
Anyways, I'll get started on reading all the info, and go from there. No rush to buy a new phone just yet (although I had it in my head I was gonna splurge on the P8 when it arrived). I'm still keen to know though, can I stick with my P3? or buy a cheaper older Pixel? I can afford a P8, but don't want to shell out if it doesn't make much sense and could get the same functionality with G.OS for less (or zero) cost.