I can assure you that it wasn't related just to rebooting as this has been something that's been bugging me for months. I had previously rebooted earlier in the day because of this exact same issue (a runaway WindowServer process), before I saw this article. I also did a fresh reboot before following these instructions too as a sort of "control".

The change only happened for me after removing Chrome as well as the launch agent for keystone.

> From my experience Mac OS tends to slow down after a few days

Just for the sake of the argument, do you have installed Chrome?

I use macOS daily for months at a time without rebooting and have not seen this problem on any of the 5 Macs I've been using for the past several years, for what that's worth. It does seem like it's something specific to your machine.

Does your system have Chrome on it, because if it doesn't then you observations don't really apply since the conversation is centered around a bug possibly associated with that. Personally I don't allow chrome on my machines. I do install brave for those cases where I have to use "chrome" because some company simply doesn't design their web app for anything else otherwise it's firefox.

The question is: Chrome, or no Chrome? xD

Yes. Just like Linux - in 1996.

Very sad.

(I have recently started using Apple tools for developping with Swift/Xcode on iPad. I am very unimpressed by the quality of the tools, and quite impressed by the range and depth of features....)