It would be good for KDE to get stronger backing, but I've heard RedHat avoids backing KDE and focuses on Gnome, due to aversion¹ to contributor agreements², is that correct in that case?
At KDE, we don't require signing CLA to contribute, this is a requirement in our manifesto[1]. But contributor can assign their right to the KDE e.V. if they want using a Fiduciary Licensing Agreement[2].
Right, but surely it's time to reconsider that. Qt has "caught up" on licensing, whereas to my eyes at least Gtk is still behind in terms of developer usability.
I recommend the KDE neon distro to every Linux-curious person I meet. It's the latest and greatest KDE on top of an Ubuntu base, and it's by far the best desktop distro I have tried in my ~20 years of using Linux on the desktop.
Just some advice: public consensus is that if you don't want the bleeding edge of KDE, Kubuntu is basically just as good (KDE over Ubuntu) and reportedly is more compatible with various hardware — so if your laptop has issues with Neon, try Kubuntu as a nearly identical alternative.
Note that you can get KDE on any major distro, e.g. Fedora, Arch. I can't recommend it enough, KDE is the dream DE — great out-of-the-box, but settings for pretty much everything, set each once and then forget it as it gets out of your way without sacrificing any feature whatsoever. There are a few minor glitches, but much less so than Gnome or MacOS or Win 10 in my anecdotal experience (notwithstanding display support, that's driver-related and whole other ballgame).
I use KDE in Debian testing for a long time already. Easily the best DE around. Though I wish Debian would get faster updates. Even though testing is supposed to be rolling (besides freezes), something seriously stalls new Plasma uploads there.
Typically, "slower" updates in Debian testing are due to the fact that the new package version has known breakage that makes it unsuitable for release, or requires dependencies to be updated and this in turn breaks existing packages (either the build, or the package itself). These situations have to be managed via a "transitions" mechanism. When in doubt, there is a tracker at https://qa.debian.org/excuses.php that reports on why a newer version of the package has yet to enter the testing channel.
Usually, but it's not the case here. In the case you described, you'll see the new upload in unstable, that didn't get to testing yet. In this case, it's simply not there at all:
To be pedantic, Neon is not a distro, it's a project made by some KDE contributors (they state so themselves) and FTR is by no means the "official" distribution by KDE.
Disclaimer: I package the KDE software stack for another distribution (openSUSE).
KDE neon is downloadable as a LiveCD with an installer, it shows as "neon Linux" in the bootloader, and you use pkcon rather than apt as a package manager.
You could add the repos yourself to Ubuntu and have something very similar, but the way it is distributed, it is absolutely a distro.
It is certainly not the official, canonical KDE distro in any way, it is just a good distro with phenomenal KDE integration.
How well does it integrate with non-Qt apps in terms of look and feel these days? Stuff like LibreOffice and Firefox, but also really any random Gtk app.
[1]: https://manifesto.kde.org/commitments.html
[2]: https://ev.kde.org/rules/fla.php