Linux

Start by checking what windowing system you're using as its a fundamental part of problem solving. It's a little confusing how to do this, the top answer in this Stack exchange thread works well.

If you're running the latest KDE then you've almost certainly been moved to Wayland and that will be the source of your problems. Wayland and Nvidia drivers don't work well together, and KDE have defaulted to Wayland in the latest release. I have had very similar issues to you with the move to wayland and have not been able to fix them - they're too fundamental and depend on updates to wayland and/or Nvidia drivers.

I know you don't want a solution but there isn't one at the moment, so you'd be wasting your time. The solution is to log out, then on the log in screen select Plasma (X11) as your session and log in again.

Personally I have had to abandon KDE as I get a different set of problems in X11. I'm on OpenSuSE Tumbleweed so have little choice inrolling back to the previously functioning version of KDE - I'm using Cinnamon instead and contemplating switching to a different Linux distro, probably OpenSuSE Leap in favour of stability over cutting edge.

Meanwhile I have the latest KDE running on another device with AMD GPU without issue.

In terms of when it'll be fixed, there is a change being made to Wayland which will effect how it and the Nvidia drivers interact (something called Explicit sync). It's just been merged into wayland so presumably will appear downstream in the coming next few months in rolling distributions. There have been articles suggesting this is going to fix most problems but personally I think this is a little brave but fingers crossed.

Try switching to different versions of your graphics driver and/or kernel. Nvidia cards get really finicky about the version matchups, especially as they age. Try different combinations of the versions that are available via pacman, and maybe it’ll work. You may need to start keeping an eye on updates to your kernel and graphics driver to see if a new update fixes your issue. Welcome to life with an nvidia card. I bought an nvidia card once in 2013. By 2016 I had to start playing this game on upgrades. At one point, the graphics driver was causing kernel panics until I downgraded both and waited a few months. Very happy with AMD.

I typically search the package name + fedora, it will probably tell me the alternative package that is in fedora.

Nowadays, I have moved to an atomic fedora distro, so I would severely limit the amount of package I install on my system for stability and security.

I think I only have two packages installed on my machine: fish, because it is the only popular shell that follows xdg dir; and a latex-like input method to use in slack.

No never! Do not use Kali as main OS choose Debian, Fedora, RHEL (not designed for this use case) or Arch system

Try paveaucontrol, it has an option to lock settings plus it's a neat app to call when you need to customise settings. You could also add user to the group that has access to mic.

You can “do” the same thing in Debian as you can arch, the main difference is packaging philosophy, Debian packages are older and more stable, while in Arch world you typically have the newest version of software packages as late as a few weeks from their release (the caveat being breakage is a bit more likely), Arch also has user repositories where the community can contribute unofficial packages

You can do pretty much the same things on either. The difference is one is a rolling release with fresh fairly untested packages and the other is a fixed stable system with no major changes happening.