Well, it's a big upgrade underneath. They're moving from qt5 to qt6. Tons of fundamental wayland fixes with the new toolkit/framework. You might be right that it's not that dazzling of a visual overhaul, but it's a mature product. We need more polish than overhaul

The migration to Qt6 and the work being carried out on Wayland, which is all going into Plasma 6.0, is going to allow massive changes that will be introduced over the 6.x series. There are some pretty cool features in 6.0, but the bigger changes will come over the next few point versions.

Are you a KDE user? I switched from Gnome 3 when Plasma 5 was new, the very moment it seemed close enough to finished to expect reasonable stability. It was a huge departure from KDE4, and after trying literally every other DE to find happiness away from Gnome (that's all I'm going to say about that) over the course of several years, it was such a welcome relief.

Plasma 5 was not only a life preserver for folks bailing from Gnome, it also showed they'd learned from their own mistakes with KDE4, which many users felt was just as much a trainwreck as Gnome 3.

There's a lot going on under the hood with the change to QT6 as noted, and that alone merits a version number change, IMO. I haven't tracked a whole lot of specific features, but I know there are a lot of wayland refinements and HDR support coming, and I'm doubtful that the many pointieststick blogposts have been doing nothing but writing about bugfixes and menu changes, even if I haven't read every single one of them.

The general default look and feel maybe isn't being radically changed, but this is Linux, and more importantly KDE; we're all about theming and customization anyway, right?

Most importantly they aren't throwing out the baby with the bathwater. They did it (intentionally or not) with 4, and then (in my perception) they were forced to do it with Plasma 5 because of KDE4.

After living through the transition from Gnome 2 to 3, and KDE 3.5 to 4, then feeling the relief when Plasma 5 just absolutely crushed it, I'm very happy to see them upgrading the undercarriage and making things generally better instead of building it all from the ground up again.

For me its all the stuff they're not writing about.

Qt6 drastically improves wayland functionality.

HDR support with good SDR tonemapping/gamma 2.2

Variable Refresh Rate support for the whole desktop

ICC color profiles

And then yes the bugs. Right click menus going partially invisible, spectacle not dumping to clipboard properly, etc. all fixed. Just gone. Poof.

because those two things are pretty much what Plasma needs the most at this point. the two most common complaints about Plasma are that it's buggy and that it's ugly.

Yeah I understand it's a lot under the hood, but people seem to anticipate it like it's the best and most exciting thing since the second coming of sliced bread. I kinda don't get it. But it's good that it's coming along. I probably won't even notice a difference.

you'd be surprised at how much of a difference that really makes

Yeah, Plasma isn't great under heavy IO and as far as I can tell that's not really getting fixed in Plasma 6. It's one of the biggest problems I have with it right now. On faster storage it's not really a problem, especially on SSDs, but on slower storage it can definitely be. I would recommend trying a different desktop.

GNOME is generally heavier than Plasma, but might indeed perform better in the scenario. You don't have to use GNOME with GNOME applications if you don't like them. You can easily use GNOME Shell and Plasma applications. There other desktops worth a try outside of GNOME and Plasma, tho. LXQt should be very fast. Enlightenment even more so.

Also, I don't think memory safety is among KDE's biggest concerns. Qt afaik handles a lot of the memory management and it is a professional toolkit which has received a lot of testing. It shouldn't be too problematic. Writing memory safe code is also much easier in C++ than it is in C. Yeah, Rust is better, but it doesn't seem to me like this is something that's causing that many problems in KDE.