If you use Plasma and find the Cube one of the most useful features and a major motivation for choosing it over other desktops, you will be shocked to learn KDE plan to abolish it at the next release (5.23.x).

Now, of course, that won't affect Devuan users immediately because the Plasma here is many versions back, so presumably will not be upgraded to 5.23 in the immediate future, but it may well bite when the next version of Devuan comes out. By then the cube will be long gone and any chance of persuading KDE to put it back will be long behind us.

I have opened a wishlist bug report at https://bugs.kde.org/show_bug.cgi?id=443410 and a topic on the KDE forum at https://forum.kde.org/viewtopic.php?f=15&t=172850 and would welcome support there.

KDE have invited those who care enough to rewrite the effect using QML, but I imagine that's not a trivial thing to do unless you know both QML and the internal workings of Plasma well.

Not that I care about DE's much, but at least the KDE folks, are willing to allow someone to make those changes, that gives me a small amount of respect for them, whether they are bloated or not, which I think they are.

That being said,  I wonder if Gnome would be as willing to preserve features people like. I am not sure...

I'm nostalgic for something I never used.

Good times. You can still do the cube on the Trinity Desktop (TDE), I think I even got it going with compiz a couple years ago if I recall correctly. I was using that awesome Devuan respin, Exo GNU/Linux. That was one incredible introduction to the world of Devuan. I'd still be using it, but vanilla Devuan is just so perfect.

Here it is - looks like I was using a hex-cube at the time:

Now, of course, that won't affect Devuan users immediately because the Plasma here is many versions back, so presumably will not be upgraded to 5.23 in the immediate future, but it may well bite when the next version of Devuan comes out. By then the cube will be long gone and any chance of persuading KDE to put it back will be long behind us.

I have opened a wishlist bug report at https://bugs.kde.org/show_bug.cgi?id=443410 and a topic on the KDE forum at https://forum.kde.org/viewtopic.php?f=15&t=172850 and would welcome support there.

KDE have invited those who care enough to rewrite the effect using QML, but I imagine that's not a trivial thing to do unless you know both QML and the internal workings of Plasma well.