It’s always worth to learn something new.

You need both. If you want to start as fast as possible, learn Kotlin first.

Everywhere except some Windows only apps.

mdam doesn’t work on either my Trixie or 26.04 install

What? Do you mean it is incompatible with Mac OS software RAID implementation? This does not mean it doesn’t work. You will also be unable to read your software RAID if you insert disks into hardware RAID device.

LOL, you could hear that about pretty much every release of any software.

Much more common than is should be.

The current stable release is Debian 13. Choosing 12 is nonsense.

If you are choosing between Fedora and Debian, definitely go with Debian. Fedora evolves too rapidly for professional use, and its administration requires excessive effort.

So what does the existing CLI do if it is not a runner?

TL;DR

Is it GUI only?