This is a bigger problem that should be fixed ASAP. OS vendors should never critically break graphics on a OS like this.
>you can't log into the GUI due to a bug in the login screen;
Again, the QA department or automated tests of your OS vendor should not let this get released. If such a bug happened there should be a fix rolled out immediately.
>you are working on a server that is headless
Why do you need to run the browser on the server? I can't think of a case where you would want to use a text browser there instead of a regular browser on your actual machine.
>so I had to boot into a system via a USB stick, chroot into the system, then install the uninstalled desktop package.
It's disappointing that you had to manually fix it compared to it just downloading a fix automatically like what would happen on Windows, Mac, iOS, Android, etc.