last week when Nvidia did an upgrade to their Linux drivers the computer no longer booted. It was like this and I understand that the issues when such things happen can be a bunch of things.
fortunately I was able to still log in and X still ran, but Wayland did not.
Wayland is the replacement for X.
so I would log in to run level 3 by changing the boot line and then I could run x by running startx from a command prompt.
Windows has no such method.
and even after a week, and discovering that I could run a different boot loader (the problem was with the mouse stalling, the input stalling) I could change to a different windowing manager (from GDM to a different one, and then I could get the log in screen and not have to go into grub everytime I rebooted my machine.
but the issue was specifically because the Nvidia driver screwed up something.
and they have not updated it since.
from time to time I'd try to reboot into Wayland, and though everything would load, and the windows were all there, the mouse wouldn't stall and the system was unusable.
That's my story about my machine and how I fixed it.
I am sure that there were a lot of linux users who aren't as advanced as I and were left stranded.
So maybe this 'global outage' is also something to do with some bug that has been inserted into some simple driver.