I am reticent to argue with someone of your reputation, but AFAIK UEFI can initialize a basic framebuffer (and write to it) in a standardized manner without needing any ROM on the card.
https://wiki.osdev.org/GOP
The GOP driver is provided by the card, and then exposes a standardised interface to the firmware.
The GOP driver is provided by the card, and then exposes a standardised interface to the firmware.