as others have said KDE is going to work the same on Fedora as it does on your current Kubuntu system. You may be thinking "oh Fedora KDE, it must be really good on that" no that's just how Fedora does things. I mean they have Fedora Sway and it doesn't mean that Sway is superior on THAT version of Fedora. it just how they roll with their distro. Like say you install CachyOS as an example and during installation it presents you the option to install pretty much EVERY DE and WM in existence. Feodra simply doesn't give you that option during install, you need to figure out which one you want to use before downloading the specific ISO for it.
So is it a better experince? it's the same experience honestly.