I’ve seen people suggest Ubuntu without mentioning Kubuntu, but it seems like most people (especially gamers?) prefer KDE Plasma. I’ve seen people complain about Ubuntu’s GUI and lack of customization, but then no one suggests them to try Kubuntu instead. It seems like people just don’t know that Kubuntu exists.
Also as an aside, people often criticize how slow updates are on Ubuntu/Kubuntu/etc, but if you enable the backports ppa then it’s actually pretty quick!
sudo add-apt-repository ppa:kubuntu-ppa/backports
I think most people just say Ubuntu to indicate the Ubuntu family of distros. A help guide for vanilla Ubuntu running GNOME should work the same way for Kubuntu with very minor changes i.e. adding a repository for the GNOME software manager vs the KDE software manager.
Except if the gui mentions anything in regards to GUI. Ubuntu and Kubuntu’s system settings aren’t even remotely similar.
That sadly makes Kubuntu a bit of a tough sell for a beginner who wants to primarily use the GUI route, since there’s a guide for Ubuntu for almost everything but not for Kubuntu.
(Which sucks, because I like KDE way more. I of course use KDE, but that makes it kinda hard to recommend Kubuntu to a total beginner.)
There are plenty of other distros that use KDE and are easy to use. Bazzite, for example, is almost too easy.