Things are more interesting in the Linux world. Plasma is just a user interface, a desktop environment. The actual operating system is Linux. And we have so many choices for how we want our desktop environment on Linux, but Plasma is the most advanced one.
I said its a linux operating system, and the whole installation from Desktop environment to the compiled kernel and preinstalled executables was carefully made by the KDE team. They literally said Operating system on their mastodon post, “toot,” this lemmy post shows. So its correct what I said