Bring back distro-wide themes!
Someone on Reddit was asking about the Bluecurve theme on Red Bait Linux.
Back then, Red Bait GNU/Linux only offered KDE and GNOME, I think. The great thing about Bluecurve was that they looked the same and both of them had the Red Bait look.
Not any more. In recent years I've tried GNOME, Xfce, MATE, KDE, Cinnamon, and LXQt on Fedora.
They all look different. They may have some wallpaper in common but that's it. In any of them, there's no way you can glance from across a room (meaning, too far away to read any text or see any logos) and go "oh, yeah, that's Fedora."
And on openSUSE, I tried all of them plus LXDE and IceWM. Same thing. Wallpaper at best.
Same on Ubuntu: I regularly try all the main flavours, as I did here and they all look different. MATE makes an effort, Unity has some of the wallpapers, but that's about it.
If a vendor or project has one corporate brand and one corporate look, usually, time and money and effort went into it. Into logos, colours, tints, gradients, wallpaper, all that stuff.
It seems to me that the least the maintainers of different desktop flavours or spins could do is adopt the official theme and make their remixes look like they are the same OS from the same vendor.