One of the biggest difference is package signing, which is often multi party where multiple developers review changes and coordinate uploads.
There are others, like how Debian and Red Hat essentially maintain forks of software which they only apply cherry picked security updates to. This blocked the XZ utils backdoor, for example. Debian Unstable, Arch, and other distros which shipped newer versions of software got the backdoor. But not Debian Stable and Red Hat.
I wrote a long post here, in which I go more in depth: https://programming.dev/post/48171483/23081855