I've been using the KDE spin of Fedora for many years!
I still use tumbleweed, but with Gnome and this has been my distro of choice for the past couple of years. (I moved from Ubuntu)
I started with arch and I just bolt on whatever desktop environment or window manager I want.
I imagine there are other things like this with most distributions.
Or for something like Plasma, you can go with Kubuntu or KDE Neon. Both of them are Ubuntu derivatives which are meant to be used with Plasma. But KDE Neon will get you the latest Plasma version, and Kubuntu will not be bleeding edge.
I've personally used it for nearly 3 years now, and never had any problems with KDE Neon. It probably isn't a good option if you'd like to have the newest versions everywhere, since the base system is only thoroughly upgraded on every Ubuntu LTS release.
If you have any questions regarding KDE software or KDE Neon, I'd be happy to answer them on #kde:kde.org (Matrix) which is also bridged to #kde on freenode.
Was seriously considering using it for my primary desktop, but that'll have to wait until there's a viable RDP alternative.
The main reason I moved to arch was KDE Plasma 5. When it first came out version 5, was buggy, but usable enough to be a daily driver. A rolling release made it easy to get the latest updates and I haven't needed to revisit my decision since the last 5 years.