I migrated my daily driver from Ubuntu > Kubuntu > Nobara (based on Fedora), and I understand that fear of switching away from Debian after investing years into its ecosystem. Even still, Nobara has been wonderful and you might end up enjoying it (or another Fedora distro) just as much as I do. Like with Ubuntu/Debian, most apps are pre-packaged for Fedora, and the switch from one to the other is often as simple as trading sudo apt install for sudo dnf install.

If your shoes, the thing I'd be more worried about is the transition from Kubuntu (with its built-in tweaks that smooth out the rough edges of Linux and offer an "it just works" experience) to bare-bones Debian. Love 'em or hate 'em, Canonical put a lot of work into their distro and it became the go-to for a reason. That's actually how I found myself on Nobara - the promise of pre-applied usability tweaks. I'm not a gamer, but I love that media players, graphics packages, OBS Studio (which I use for Zoom meetings at work), and my condenser microphone all work out of the box. And then there's the gaming stuff as a cherry on top.