I also spent some time messing around with the Chameleon skin on Mediawiki. First time I had a serious look at it.
This skin uses Bootstrap 4 and if I'm following how it works, it basically allows you to skin/theme/layout a Mediawiki site any way you like.
You know how pretty much all Mediawiki sites look the same regardless of what skin is active? This allows you to change that.
It's a bit of a pain to install the Bootstrap extension and the skin itself in the official docker container. I don't know why this is not made a default or accessible via a tag. It should be - from what I've seen this should be considered a leading feature for MW.
Just scratching the surface but looking forward to doing something to modernize the look of my internal wiki. The Medik skin is cool and all but it sill looks like MW ultimately, even with colour and font rotations and such.
Poking around, my MW instance is 12 years old and has ~1100 pages. Nutty.