In short: Google Chrome installs the Keystone module, which slows down your computer and for some reason hides from Activity Monitor (the process manager in macOS). Your Mac slows down even when Chrome is closed. Removing Chrome and Keystone fixes the problem. How to completely remove Google Chrome and Keystone.
In detail: I noticed that my new 16-inch MacBook Pro started lagging even when scrolling pages in Safari or browsing folders in Finder. Activity Monitor showed nothing unusual about Chrome, but WindowServer was consuming ~80% CPU — way too much (normally it's under 10%).
After trying every standard fix (quitting apps, logging out all users, restart, PRAM reset, etc.) I remembered I had recently installed Chrome to test a website.
I uninstalled Chrome and Keystone. Removed everything Google-related. Restarted the computer. The result was immediate — the Mac became much faster, and WindowServer dropped to under 10% CPU.
Before my Mac started lagging, my family had been complaining about poor performance on their 2015 iMac practically since day one. I tried everything I could think of, but nothing worked.
Then I remembered that installing Google Chrome was always one of the first things we did when setting up a new computer. I removed Chrome, all Keystone files, restarted the computer — and it worked like new.
Yes, I know it sounds like an ad, but it worked so well that I registered this domain to spread one message — "Google Chrome is bad".
/Applications and delete the Chrome browser (you can use a cleaner app like CleanMyMac).Finder, click Go in the menu and select Go to Folder..., or press Shift + ⌘ + G./Library and press Enter.
LaunchAgents, LaunchDaemons, Application Support, Caches, Preferences.Google, com.google... or com.google.keystone....Go to Folder... again.~/Library and press Enter (don't forget the tilde ~).
LaunchAgents, Application Support, Caches, Preferences.Google, com.google... or com.google.keystone....Safari is excellent and already installed on your Mac. If you need a Chromium-based browser (the engine Chrome is built on) — try Brave or Vivaldi. Or Firefox.
Keystone was first reported back in 2009 when Google bundled it with Google Earth. Even then it was doing strange things, uncharacteristic of an auto-update program.
The fact that Keystone's performance still hasn't improved (in over 11 years!) might mean "it's not a bug, it's a feature." Why would an auto-updater use so many CPU resources — and hide it?
To all the good folks at Google who work on Chrome: something is happening between the code you write and what ends up on users' computers. Hopefully you can find it and make it public.
Original: chromeisbad.com.