> A project like F-Droid is dumb to begin with where they're the one to build the apps.

I heartily disagree. Linux distributions also build the packages themselves, and that adds a layer of trust.

It ensures that everything in the fdroid repo is free software, and can be self-built.

They don't. The community builds the packages.

There are other ways to ensure something is free software and can be self built. Their approach is highly inefficient.