That's always a fair point, but you can at very least pick your poison (hosting provider), and it's very portable to switch between them. Or if you want to, set it up on your own physical machine. I don't know enough about network security to run a publicly facing server from home, and I don't think I'll take the time to learn it any time soon. However, I may well end up running it at home at some point soon in a way that's only accessible from home, for truly private things like contacts. A nice in-between could be a community center intranet. (Though setting up auth within an intranet isn't easy yet)

To your point, I'd be curious if the data selling/using policies of Linode vs Google Cloud are different.