What causes macOS to stop launching any apps?

I don't get error messages and the apps I have open still work fine, but my Mac is refusing to launch any new apps, including terminal.app. - It doesn't matter if I try to launch an app through spotlight search, the bottom bar, Finder, or if I use Show Package Contents -> macos -> click on UNIX file. - I tried to get around this by opening About this Mac and clicking Displays Preferences to open System Preferences, but now About this Mac is stuck permanently open with the spinning mouse wheel whenever I mouse over it. My system is M1 Macbook Air 11.2.1. Normal restarting doesn't help, since the OS reopens the programs I have as start-up applications.