It gets even more frightening if you realize that you're probably not even considering all of the "deeper" levels. Almost everything I listed in my comment was pretty surface-level stuff, where it's at least somewhat obvious that you're giving the data to them (some things like the analytics not so much, but still not really "hidden").

But now start thinking about some other things:

- Are any of the sites you're using hosted on GCP (or other Google-owned hosting)?

- Even if they're not, do they include any scripts/images/fonts/etc. from other sites that are?

- How much network infrastructure does Google own now? How much of your traffic is passing through it?