My understanding is that the problem with RHEL clones is just that, that they are clones.
From what I've read, the problem is that RHEL will often make changes to suit their various enterprise customers, for example I seem to recall reading somewhere that OpenSSL was one of many things "touched" in that way.
I hear many good things about DNF vs apt, but I'm too worried by the skeletons in the clone cupboard.
> There's also SUSE.
So, why doesn't SUSE get close?
It's terrifying actually.
That's not really true. They often ship with Red Hat specific software (like Podman is) replacing widely used software (e.g. Docker, to which Podman still isn't feature complete even though it has been shoved in everyone's throats for a couple of years now), but "more modern" will vary wildly based on the release date.
RHEL and its clones are supported with updates for 10 years, often ship with "more modern" server software than Debian does (e.g. firewalld, podman, systemd etc) and DNF, whilst slower, still blows apt in terms of feature set (e.g. transcriptional, roll-backs, history, offline upgrades)
There's also SUSE.