Look in /var/log/Xorg.0.log for Xorg errors.
Check if OpenGL is okay by running glxinfo (from the package mesa-utils) and checking in the first few lines for “direct rendering: Yes”.
Check if Vulkan is okay by running vulkaninfo (from the package vulkan-tools) and seeing… if it throws errors at you, I guess. There are probably some specific things you could look for but I’m not familiar enough with Vulkan yet.
You could sudo dmesg and read through looking for problems, but there might be a lot of noise to sift through. I’d start by piping it through grep -i nvidia to look for driver-specific stuff.
Might be worth running nvidia-settings and poking around to see if anything seems amiss. Not sure what you’d actually be looking for, but yeah.
Sometimes switching from linux and nvidia to linux-lts and nvidia-lts can help if the problem is in the kernel or driver. Remember to switch both of these at the same time, since drivers need to match the kernel.
You could also try switching from the nvidia drivers to nouveau. Might offer temporary relief and help narrow down where the problem is, at the expense of probably worse performance in heavy games. Ought to be fine for 2D gaming and general desktopping.
Trying a different window manager is always an option. Don’t know how much hassle that is when you use a full DE; I’ve always been the “just grab individual lightweight pieces and slap 'em together” sort so I don’t have any real experience with KDE. But yeah. Find out what the right way to change WM is for your system, then try swapping over to Openbox or something minimal like that and see what happens.
Related to WM/DE, it could be an issue with the compositor maybe. Look up whatever KDE’s compositor is and see if you can turn it off and run a different one?
Yup! The ones I clicked with genuine motives were all Project Wonderful ads. Project Wonderful was an ad service that catered specifically to creative projects, mainly webcomics. People running webcomics would host a Project Wonderful ad widget on their site to make a little extra money, and when they had some money to burn they’d pay to have ads for their own comic run on other people’s sites. I often discovered fun new comics this way. It’s the only ad service I’ve ever actually appreciated. I was sad when they shut down.
I’ve also clicked some other ads in an un-genuine manner. These were all advertisements for dresses, swimsuits, skirts, etc. The purpose here was to convince the advertising agencies to stop plastering random shit all over the internet and instead decorate it with a bunch of pretty clothes and sometimes pretty models wearing those clothes. Worked pretty well, as long as I remembered to click an ad or two every few months.
I haven’t done this in a while though. I wound up house-sitting for family members a lot in the last couple years, meaning I’d end up stuck using my laptop for a few days or a week instead of my real computer. The laptop has a lot less ram and runs into problems browsing the web sometimes due to ad company programmers being incompetent fuckwits who write leaky code. I finally got fed up with this and installed uBlock Origin on my laptop to make it more usable while away from home.
That was all I’d intended to do; I was fine coexisting with most ads on my desktop and just using custom scripting to nuke individual specific ad slots that were being nuisances (e.g. jerking the page around on wikis I frequented). But since I have Firefox set up to synchronize between my laptop and desktop, I incidentally wound up with uBlock Origin on my desktop as well. I’m not sure if there’s a way to have that be asymmetric while still having all the other browser extensions continue to synchronize (because I would prefer if websites kept getting paid for my traffic when I browse on PC, especially webcomics), but for now I’ve just happily enjoyed not having ads anymore. The internet is so much more peaceful this way. Though I do sometimes miss all the pretty dresses.