

Despite it being their software, they don’t maintain this part. It’d be like saying Firefox is responsible for preventing fake bank websites from existing (this is ignoring how they also ship malware protection lists anymore to try and help). The Discover app is just a client where a distro supplies the software lists. On OpenSUSE it browses SUSE (and Flathub, if you add it.)
On Ubuntu it browses Ubuntu’s APT repos and snap.
You can easily alter what repos the software uses too, it’s just using whatever the distribution has configured it to use in conf files and repo lists.
Yeah, I use Authentik currently and the main reason is simplicity of having it with LDAP. But I’ve considered running something else backed by FreeIPA to get more compatibility for LDAP. I feel like I have to fight to get something to work with it.
But it has some high overhead for sure.