1) Android: Google still owns all our phones. Even on rooted phones it hard to remove google services that god know send so many requests containing whatnot to the eeee addresses. Just install no-root firewall and you will be amazed the amount of pending requests that accumulate in 1 hour.
2) Google search: I guess I can manage with DDG but when it's not that straight forward search, subconciosuly I'm still thinking that let's just do a quick google search to see if i'm not missing anything. And often I find better results. While adblocks makes sure I filter most of the crap.
3) Gmail: Yes there are alternatives but switching emails is hard. It's a big commitment for most people to switch a 10 year old gmail address. And it still works great at filtering spam and whatnot.
And same for maps, youtube and all their services.They really have a big leverage on everyone.
Quiting facebook and instagram was child's play in comparison. I haven't logged in for almost an year now. Quitting google is really hard otoh.