hemlockiv Yes, they build and sign apps so there's one root of trust instead of dozens.
That is the wrong conclusion. You're still trusting the developers. F-Droid themselves acknowledges this.
The fact that they build and sign does 2 things:
It introduces an additional trusted party.
It makes it impossible to verify that the app you're installing wasn't modified from what the developer provided, or that it even came from the developer at all.
You're putting a lot of trust in F-Droid, but that does not substantially reduce the trust you're also putting in the app developers.