I use my existing Google account with with GOS, which I used for about 2 months beforehand after coming from IOS. I deleted and turned off what I could and then stopped worrying about it.
As with any community, there will be extremists and people with different threat models and use cases, you don't have to be 100% Google free, it's entirely up to you. I personally don't mind google having some data and I genuinely like some of their products and genuinely need some others. I like Google Call and Messages and think they're useful and secure compared to not using them. Pixel camera is excellent, so i usr that with Photos (network disabled + Storage Scopes). I also need a decent mobile office solution, so I use Drive, Docs and Sheets which don't require many permissions and I don't need them to be 1000% private, just secure from the outside world. I may as well use them instead of MS Office, who I don't trust at all and who do collect your data in an arguably worse way than Google. Most of my personal docs or ones I'm finished with get moved to Proton Drive.
That's a very different setup to using Stock Android, Chrome, YouTube, Gemini, Wallet, Maps etc etc and letting Google create a detailed user profile.
It's also worth noting that not all Google products are created equal, some are worse than others for data collection.
I've had GOS before and went 'hardcore mode' with no google and no play service and it was a nightmare and completely ruined my smartphone's ability to be useful. YMMV.