KDE Plasma 5.13 Released (kde.org)
jrepin writes: KDE unveils the final release of Plasma 5.13, the free and open-source desktop environment. Members of the Plasma team have focused on optimizing startup and minimizing memory usage. Plasma Browser Integration is a suite of new features which make Firefox, Chrome and Chromium-based browsers work with your desktop. For example, downloads are now displayed in the Plasma notification popup, and the Media Controls Plasmoid can mute and skip videos and music playing from within the browser. Browser tabs can be opened directly using KRunner via the Alt-Space keyboard shortcut. System Settings design has been improved further. Window manager gained much-improved effects for blur and desktop switching. Wayland work continued, with the return of window rules, and initial support for screencasts and desktop sharing. You can view the changelog here.
I remember when Microsoft had a feature called "Active Desktop" (I think) where you could embed webpages into the desktop. So when the embedded Internet Explorer invariably crashed it would take down the desktop. Brilliant engineering. It is only a matter of time before some Millennial comes up with the same idea.
I'll stick with KDE4 still.
"KWin does not provide window tabs" -- https://community.kde.org/Plasma/5.13_Errata
Here's my two cents annecdote. I'm currently running Plasma 5.12 on openSUSE Tumbleweed. I have a computer for my wife that runs Ubuntu Mate. KDE feels right in line with the speed of Mate. That was not the case in the 4.xx series or early 5.xx series, but since around Plasma 5.8 it has been exceedingly smooth. Now are XFCE/Mate type desktops perhaps a little lighter? Maybe. But I'd think you would be pleasantly surprised by the speed of KDE these days. But if XFCE is your style then no reason to switch.
I too suffered under broken resource-hogging Akonadi for a long time under Debian.
Then i switched to Arch and Akonadi flies completely under the radar, unless you check for it you would never know it was there.
SO many distros are Debian-based, I think they all inherit the bad KDE builds that Debian makes.