Microsoft has pinned a Copilot shortcut to my taskbar after an update multiple times.

One time they replaced my "show desktop" button in the bottom right with a Copilot button.

That's called malware. Like that's literally malware by any reasonable definition. The fact that it's branded by and distributed by a multi trillion dollar corporation does not make it not malware. Your PC has been compromised, and it would be wise to solve your problem instead of trying to make the best of running malware.