Last year i ran GOS for 6Months.
Yes you have to put in extra work to stop adtech, but its possible (depending on your usage)
Then i switched back to stock.
I never had my mind at peace since (a bit exaggerated maybe).
The things you have to do on OS level to get the same privacy from GOS is just impossible. Even if you try, you'll never now for sure what you Phone is doing in the background.
Finally switched back to GOS, setup my humble 10$ monthly donation via github and will never look back.
The only thing i want to be able is to be in control of what my phone is doing. Nothing more.
I use MullvadVpN with Ad/Tracking blocking on DNS level. This is good enough for me. Just be aware what apps you are using and what data you give them willingly, not Ad/Tracking Blocker can save you from that