Google services are unfortunately pretty important to most users day to day life. I have tried degoogled android but have always come back to graphene.
I stopped using google completely several years ago. I deleted my accounts and information.
I created a burner for YouTube since there’s no other option but otherwise I refuse any google software (and I use iOS).
Then apple is just collecting your data instead of google, they just give an illusion of better privacy. Both make most of their money from advertising.
There are definitely ad supported apps on iOS, they also control the core of all browsers on iOS. Neither Apple or Google really sell data externally, they serve ads to their audience using algorithms trained off vast quantities of user data. Selling the raw data is a bad way to do it because you don't have control over it after the first sale. Keeping it internal and selling your services is a much more lucrative way to do it if you have a big enough platform. Chromium is google's way to spy on you online and serve ads, webkit is apple's. Google allows non chromium browsers on android but apple requires that all iOS browsers are basically just a reskinned safari.
It feels fine, if you don't use google apps you wouldn't notice a difference. But the last time I seriously tried using it as a daily driver was probably three years ago though. MicroG is ok but just can't compare to the sandboxed gapps in graphene when it comes to compatibility.
Pixel phones completely stock are a privacy nightmare, but are ironically the most secure phones on a hardware level, which is why GrapheneOS devs chose them.