I used the file manager and the gallery apps but I stopped using them since they started to reduce functionality to nudge people to the paid versions. Of course there is nothing wrong in working for money, I do, but I replaced them with other open source and free as beer apps from F-Droid. Selling open source is hard. To put it mildly, there is lot of competition on price. Selling closed source is hard too, because of competition from open source.

I'm using Material Files and Aves Libre now. Aves doesn't have an editor and I'm using either the one from Samsung's Gallery, which I can't remove anyway, or Google's Snapseed. Google can snoop on me with the OS and the other apps of them I'm using (almost only Maps) so I'm not worsening my privacy level too much.