2) The F-Droid maintainers manually build the apps on F-Droid from the respective code repositories. They will notice when something like that is off. This has to do with it being FOSS.

And if you're wanting to tell me that this doesn't scale, not really, no, but it's the same thing that Linux distros have been doing for a long time and Red Hat, SUSE, Canonical actually do have a crapton of users, especially on the server side.

Every one of those distros gets around volume of desired apps by allowing the inclusion of third-party repos (e.g. current Python or docker) which in turn introduces typo squatting as a vector.

You're asking for app store maintainers to slow everything to a crawl and never get popular. No entity which wants to be successful will do that, corporate or otherwise.