I had another comment refuting the GP (as you are), but the more I thought about it, I decided to delete the comment.
At the end of the day, you have to pay $99/year to publish on the Apple App Store, and on Android, although Google has had some shady practices around automatically flagging/removing apps from it's store, you have more options in terms of app distribution, such as F-Droid.
To my (now deleted) comment's point though, I don't see much of a relation between F-Droid and NewPipe, besides that F-Droid hosts it.
EDIT: other comment on this thread answers that last point I made and your question, and sums up what NewPipe has to do with the "openness" of the platforms [1]. However, I now wonder, what is stopping Google/YouTube from going after NewPipe & F-Droid?