One thing worth noting, these checks and restrictions only apply if you're using the original F-Droid repository.
Many times I've seen the IzzyOnDroid repository recommended, but that repo explicitly gives you the APKs from the original developers, so you don't get these benefits.
That's true. The whole point of an open ecosystem is that you get to decide who you get your software from. You can decide on the official F-Droid repository and get the benefits and drawbacks of a strict open source rule with the F-Droid organization's curation if that's your preference. You can add other repositories with different curation if you prefer that.
Many times I've seen the IzzyOnDroid repository recommended, but that repo explicitly gives you the APKs from the original developers, so you don't get these benefits.