Valve's Steamdeck uses Plasma for the Desktop Mode. It's still 5.x though. I can't wait to see it get updated to 6.1. The Plasma teams really has been putting in lots of ease of use improvements.

Kubuntu 24.04 is also still on 5.x

If you want to use this on a distro it will have to be a rolling version like Arch or KDE Neon which is 22.04 plus the latest KDE packed by KDE devs

Or Opensuse Tumbleweed. Kinda like Arch but without the blood

The Steam Deck OS is based on Arch but the developers roll out releases at their own pace.

Nice! I recently perma-switched to linux and KDE has come so far from its v3 days, where to be frank I just didn't like it much. Definitely enjoying it now though. Its very usable, customizable, and mostly consistent.

What distros will get this version soon?

I read yesterday that for kubuntu it will take months.

OpenSUSE Tumbleweed, Fedora, ArchLinux. Kubuntu 24.10 will have Plasma 6 in Fall.

KDE Neon is by the KDE team, so it should be updated pretty soon, if you want an Ubuntu-based distro.