GNOME always seemed like an odd choice considering how little customization is available. It feels like a prescriptive approach, you will use your computer the way GNOME feels is appropriate, whereas KDE tries to accommodate however you want to use your computer.
Back in the Gnome 2 days this wasn't as much the case. Plus KDE was kind of a mess back then so the main choices were Gnome or XFCE which had fewer features. When Gnome 3 came around the devs switched hard to a much more opinionated approach, leading to Gnome 2 forks like Cinnamon since KDE was still very underpolished. It's a bit regrettable that all that effort was poured into Gnome forks instead of improving KDE especially considering how great it is now.
Having a company behind software means you can pay to have your bugs fixed. Big distros want that stability for their corporate customers. It's no secret or anything. KDE has sponsors, but doesn't have a direct relationship with a huge contractor like RH. Same reasoning for systemd.
I wonder if the Gnome team's cavalier aditude towards agreed upon standards is related to Redhat's influence 🤔 It's totally possible the devs are just high on their own fumes due to being the default for so long.
This is the advantage to GNOME. I know that all I need to make a Linux desktop work the way I want is to install GNOME and GSconnect. I really like default GNOME, adwaita, and the actually usable out-of-the-box experience. Sure there's a learning curve but that's true of every desktop and I really hate the context menu hell that KDE imported over from Windows.
Not to mention there are still a lot of amateur mistakes over at KDE like the recent themes fiasco.
People who want the customizability of KDE will use the KDE spin or a distro that ships it by default. People downloading a massively popular distro like Fedora should get something as maximally functional as possible out of the box, and with all the stuff they've been adding recently, GNOME is more and more polished almost to a macOS point. I just recently found the built-in RDP, SSH, and filesharing toggles in the settings menu, and they're easy enough that I'd actually call GNOME quite beginner friendly at this point.