Best decision of 2017 was deleting my Facebook account. I encourage everyone to do the same. Next step is getting off of Gmail / Google Services, which I also started last year by using duckduckgo full-time.
Also i gave up Google search a long time ago. DDG at the time wasn’t good enough so I moved to Bing. I stuck with it through now. I do have to use Google for certain hard searches or roughly 5% of the time.
On Android I had to buy CardDAV and CalDAV sync apps. They're cheap and it is a one off fee.
Works well for me!
I particularly like that Android (like Palm back in the day) has central calendar data. So I can still use aCalendar+ as my calendar app. And Ocado (grocery delivery) app can still add delivery slots, even though I've changed calendar provider.
It's super satisfying to have all Google account syncing turned off on my phone.