KDE, but it seems I soft-broke it as well while installing after regular Gnome Ubuntu. Now I'm installing Kubuntu on my laptop and will try out any other distro on a new SSD I bought for my desktop.

As others pointed, doing stuff in a rush and blindly using guides and pasting commands makes everything more difficult. No matter how robust or good the UI is lol

Speaking of myself, I think I'm just too lazy / have too little time and energy to slowly troubleshoot everything.

I am always on a rush, and when you're on a rush and something like apt not working happens, you just implement some workaround that maybe makes everything worse or is not a full solution. As others pointed, putting commands you see on Google without fully understanding them is a bad idea, and a lot of my "Linux troubleshooting experience" is "trying a bunch of Google solutions in a trial and error fashion".

For example a base issue I have with my current installation is that I firstly installed Ubuntu and then installed KDE, instead of installing Kubuntu, and the installation is kind of glitchy. I never put the time to fix the issues that maybe were not that difficult to fix, but they were unimportant and it just worked. That stuff slowly accumulates over time until the fresh install with that characteristic "this time will be different" feel lol

Basically, FB Messenger used to be based

I did not