The window management and dolphin for file management for one. KDE let's you easily pin windows on top, show on all desktops etc .. Dolphin gives you a nice multi tab, split pane file manager along with a terminal that follows you along.

On my work macbook - I can't install third-party software and the default window management is just not there. It has problems restoring windows to correct size when i switch external monitors... The experience just isn't as nice as KDE on my home laptop.

I had to install inputactions to get mac like touchpad gestures on my home kde set up but after that it just feels nicer and smoother than my office mac

Long time ago, that was actually very easy on Mac, via SIMBL (https://github.com/albertz/simbl) and Afloat (https://github.com/rwu823/afloat) and you could hack around using FScriptAnywhereSIMBL (https://github.com/albertz/FScriptAnywhereSIMBL) or Pyjector (https://github.com/albertz/Pyjector).

But that doesn't work anymore since a while (I guess due to SIP).