This sounded harder to do than it was in my experience. I figured the alternatives to their products would be less polished. But I switched to Firefox and honestly prefer it to Chrome. (They allow extensions on Android, meaning adblock, which is a game changer for me.) DDG for search is great. Protonmail for email is fine, etc. There isn't much in the Google ecosystem that I miss tbh.
The only thing I have problems finding something that works is Google maps. As an Android user there are a few different options but Google did make a damn good maps app.