I'm not sure I'm making any better argument, but technically it's 2nd party. If I turned on a Google feature, that's between us. And honestly that's kind of the point I'm trying to make. Enabling a feature doesn't mean I want anyone to have access to that features data.
I don't have a direct source but I found some other posts that suggest many people are unknowingly turning it on.
"While this feature is turned off by default, many of Google's services and apps require it to be turned on, so unless you're actively keeping it off, there's a good chance it's enabled for your Google account." https://www.xda-developers.com/google-location-history/