The branding does a major disservice to this application - it works like a charm on my windows and i3wm setups, having no trouble sharing a clipboard and files. There are very few features if any that only work on KDE.
Sometimes on windows it needs a click of the refresh button to get going after connecting to a network. The discovery is wonky on some platforms.
Legacy KDE apps used to follow this naming convention until the late 2000s, early 2010s.
You had apps like Konqueror (web browser, file manager), KMail (email client), Kompose (music score editor), KImages (later rebranded to Krita), and KDevelop (software dev IDE).
Modern KDE apps dropped the 'K' prefix and moved to a more recognizable scheme, like: Falkon (web browser), Dolphin (file manager), and Okular (document viewer).
As you can see, its now a mix of whether the app keeps the 'K' in the name. Some do not.
Its been plasma since 2009, a year after KDE 4 came out and they rebranded a bunch of their projects. Whether 16 years amounts to "ages" ig is up to interpretation.
KDE 4.4ish (early 2010) was when it finally started to become stable enough to be mostly usable, so that's close enough to just saying "KDE 4".
Unfortunately it's looking like KDE 6 is going to be another catastrophic upgrade, unlike KDE 5 which I barely noticed. Both of my Debian bookworm->trixie upgrades had showstopper bugs that required the terminal to fix KDE, there is multi-second lag unless you turn off some of the new features, and significant uninvestigated breakage remains even after that.
"Plasma [i]s Hell" is well-named, not that it's the only problem.
Sometimes on windows it needs a click of the refresh button to get going after connecting to a network. The discovery is wonky on some platforms.