There is a long abandoned (but it still runs) project called eDEX-UI (https://github.com/GitSquared/edex-ui) which basically provides a working, useable terminal surrounded by all sorts of the crap visual appearance of hacker terminals in the movies. Pair that with a terminal editor and you’ve almost got a movie IDE!
It’s kinda fun for a while although I’d be amazed if anyone actually used it as their main terminal emulator program. But you could.
GRUB (or any other bootloader) doesn’t care about and in fact doesn’t even know about X, Wayland, or any other userland GUI system.