Hey @Josh47, sorry for the frustration!
The FigmaAgent starts itself for font access & to allow you access to any Figma links without having to log in. If you don’t need either of those, you can force quit Activity Monitor, remove System Preferences > Users & Groups > Login Items
Then, delete ~/Library/Application Support/Figma/FigmaAgent.app & /Applications/Figma.app/Contents/Library/FigmaAgent.app
If you’re still getting the FigmaAgent on restart then you might have a corrupt .plist file. To remove this, try running a Spotlight search and delete system preferences plist from User library > Preferences > com.apple.systempreferences.plist
The file path should look like this:
/Users/Username/Library/Preferences/com.apple.systempreferences.plist
You might also want to delete the login plist if you have it
/Users/Username/Library/Preferences/com.apple.loginitems.plist
Alternatively, you can click on Go in your systems toolbar > Go to folder > and type in the path name (keep in mind Username should be replaced with your own). Then, restart your computer. These files will come back as new (without any corruption) and you should be able to completely remove the FigmaAgent service from login items without any issues.
Please note that Figma will automatically reinstall the login item when you upgrade the Figma desktop app. The only existing, temporary solution would be to uninstall the desktop app and use the web browser.
Our team already has this logged as a feature request internally, but to be transparent, there are no immediate plans on the roadmap to implement.