You are right but just as the original commenter said, even if you pay there is no way to be sure the app you just paid for isn't harvesting and selling your sweet sweet usage data. Like Tiktok I'd imagine would 100% do.

I am at a point where I'd really like to support and pay for apps, even closed source ones, just so they don't show me ads or harvest my data. Open source is much better at that, of course.