Every single week I have to refuse enabling back up for my pictures on my Google pixel. I refuse it today, next week I open the app and the UI shows the back up option enabled with a button "continue using the app with back up". Somebody took the time to talk down my comment about this being a strategy to give their AI more training data. I continue believing that if they have your data they will use it.
Because that's an insane interpretation of what's happening.