[BonsaiDen]

Plus the fact that you can't directly write to VRAM at all times and have to wait for the corresponding access windows.

But it's also a big contributor to the general art style and gameplay limitations for which the games of that generation are known for.

However with a few tricks drawing vector like graphics is possible[1] (to some degree), even though it requires a huge amount of lookup tables to be anywhere near peforment :D

[1] https://gitlab.com/BonsaiDen/vectroid.gb