Upstream images vs bazzite: https://github.com/ublue-os/countme/blob/main/growth_upstream_with_bazzite.svg
My prediction: bazzite may have more installs than Fedora KDE by the end of the year.
In normal repos they also test their packages. I do not think it is possible in any distribution repo to ship a binary which did not compile. Dynamic library linking may have some problems I guess, but unless you're using arch that is generally never a real problem with package manager installations. I have never got a package which plain does not run.