[granitosaurus]

or run trusted open source apps, preferably built from official upstream source.

It's a bit crazy but I liked Stallmans analogy that back in the day computers didn't need user passwords, because logically speaking the person who sits in front of the computer owns it - it's extremely empowered idea. This applies well to this subject as apps should be the same - they should be able to do everything you are able to do on the machine. You already gave full trust to the app once you installed it, to somehow go back on this trust is nothing but a paradox.