The reason this is feasible now, is that KDE is changing the release cycle for Plasma, Frameworks, and the Apps to all be aligned with the sometime-before-the-distro-release 6-month cycle, that allows for a release of everything KDE to be taken, tested properly, and released with the 6-month release cycle for Ubuntu, Fedora and other distros following that release cycle. Until recently, we would have the releases of these components all separate throughout the year, meaning that it would be harder for the distros to package, test and ship Plasma as a flagship desktop because of stability concerns (also because of bugs).

Now, with Plasma 6 being all about making Plasma better and more stable, especially in the Wayland department, I'd say Plasma is superior to GNOME in every way (except funding). At this point, it's not too unrealistic to see distros consider the switch to Plasma, including major distros like Fedora, as seen here. I really think this is the best time to consider using Plasma over GNOME.