People mostly seem to like KDE Plasma more than GNOME, but Ubuntu still seems way more popular. Will Kubuntu ever overtake Ubuntu? Will people ever default to saying Kubuntu instead of saying Ubuntu even when speaking generally about *buntus?
Same questions for other distros like Fedora/Fedora KDE
No. There are two major DEs and it’s them. I see neither is going anywhere and more often than not, both are offered to choose from. I think GNOME is often picked as the default because it’s all about simplicity and that makes sense for business-oriented distros like Ubuntu and Fedora