My understanding is that modern hardware is significantly more complicated at the lowest levels and (at least generally) no longer has a dedicated framebuffer (at least in the same sense that old hardware did).

Modern hardware still generally can be put into a default VGA-compatible[1] mode that does use a dedicated framebuffer. This mode is used by the BIOS and during boot until the model-specific GPU driver takes over.

[1]: https://en.wikipedia.org/wiki/Video_Graphics_Array#Use