I've been using arch for a while now and I always used Flatpaks for proprietary software that might do some creepy shit because Flatpaks are supposed to be sandboxed (e.g. Steam). And Flatpaks always worked flawlessly OOTB for me. AUR for things I trust. I've read on the internet how people prefer AUR over Flatpaks. Why? And how do y'all cope with waiting for all the AUR installed packages to rebuild after every update? Alacritty takes ages to build for me. Which is why I only update the AUR installed and built applications every 2 weeks.
The link you sent says that its an option that can be turned on or off. Also, that's for uploading. Doesn't say anytbify about verification of downloads.
It is recommended that OSTree repositories are verified using GPG whenever they are used. However, if you want to disable GPG verification, the --no-gpg-verify option can be used when a remote is added.
I'm confused why you think it would be anything else, and why you are so dead set on this. Repos include a signing key. There is an option to skip signature checking. And you think that signature checking is not used during downloads, despite this?
You know what else we shouldn't assume? That that it doesn't have a security feature. And we additionally then shouldn't go around posting that incorrect assumption as if it were a fact. You know, like you did.