The biggest thing I de-Googled was gmail. I had my own domain already so it wasn't tough to move (to my web hosting provider's included email service).
I switched to Firefox+uBO from Chrome.
They de-Googled RSS for me (now on Newsblur).
Things I still use:
- Drive for backups (but have a local backup in case their AI bans me)
- YouTube Premium (I hate ads)
- Contacts (Cardbook addon for Thunderbird works well with this)
- Calendar (Thunderbird supports natively)
- Keep (Shared shopping list)
- Pixel phone (I don't really care for Apple, either)