Circa 1985 hardware has significant limitations and it's leaking through abstractions both ways. A modern program supporting deep color writes to an array consisting of R16G16B16A16 values, next to a legacy program writing R8G8B8 and even a window with 10-bit 4:2:0 YUV HDR video. On the Amiga, the hardware leaks through by having to deal with separate bit planes and palettes.
Similarly, the 3D hardware in a modern GPU easily upscales a legacy application's surface 1.25x to handle the mid-DPI laptop screen I'm using right now. 1985 hardware can't do that, because you're fiddling with the DAC output, you can only have one screen/ViewPort scan line, no overlapping regions, and if you look carefully, blank lines between regions for the hardware to reconfigure.