By 4.10 or so KDE 4 had matured to KDE 3 level and this hasn't changed with Plasma 5.
The problem with newer versions of GNOME is, you get what they give you and you better like it cause that's all she wrote.
We get it, you want the classic desktop paradigm. Nothing wrong with that, but that ship has sailed years ago with regards to GNOME.
And why shouldn't people implementing GNOME for free have fun and experiment. Nobody wants to implement windows 95 for fun.
But every other group of people with a new GUI idea that thinks "Nope, we're gonna reinvent the wheel and make a new weird GUI just because". Linux on desktop is already what, 1% to a max of 2% of desktop market share world wide? And then you have people building weird stuff on top of xorg or wayland that is used by one percent of that one percent just for the sake of being different.
If it's intended and promoted for technically sophisticated users to play around with? Sure, great idea I suppose, the more the merrier. But so many of these concepts are pushed as a "better, easier to use, more user friendly for noobs" GUI, when in fact all it does is split the market and confuse the end user. In particular I'm thinking of the various efforts that have been made to clone the MacOS user interface, including the Dock.
I should note that my opinion above also applies to Windows 8/8.1, which was clearly a misstep, as evidenced by Microsoft returning to a much more classic desktop environment design for Windows 10. At least they acknowledged what went wrong and backed away from it.
Sort of like a GUI version of this: https://www.youtube.com/watch?v=bsFzc0wAtFs
That might be the tragedy of IT: unlike, say, traditional japanese joinery, traditional computing is not (yet?) a thing, and it really should be.
It's interesting to compare with a default XFCE4. You have a quick launcher which is pointlessly distinct from the taskbar, taskbar is at top wasting vertical space, and also maximized windows have their title and menu bar wasting even more.
Also what you mean with _traditionally designed desktop_? Unity takes inspiration from Mac OS (dock, global menu) which had a desktop-oriented metaphor and predates any popular desktop environment.
It was the application of better concepts from both OSX and Windows. That was it strength. Top menu (better mouse usability), HUD (better keyboard usability), grid virtual desktops (better visual muscle memory), and so on. Nothing there was new or unique. But it was more ergonomic than the alternatives now.
I still miss the HUD, and the reason I use Gnome is support for autorotation, and other hardware features. And the fact that Unity now is a dead end.
It seems you did not use Unity, and you were part of the group of people who caused its demise by endlessly complaining.
But of course, Gnome is the default in many Linuxes so I understand how easy it is to just flow with it.
What is wrong with a more traditionally designed desktop metaphor such as how it's implemented in XFCE4 or LXDE?
As a baseline for comparison I've used very nearly every linux or BSD based GUI desktop (on top of xfree86 or xorg) that has existed in the past 20 years, since the earliest days of KDE2 and Gnome. And I'm presently using a fairly normal XFCE4 setup.