Our industry was once capable of building entire operating systems that ran in significantly less than that.
For an iPhone 12 (which shipped with iOS 14) just the 2 framebuffers for a double buffered display will take up the 15 MiB. Operating systems that are "significantly less than" 15 MiB would not be suitable to run a modern personal computing device.
Layer upon layer upon yet another layer of abstraction have made it so nobody sees the turtles the whole thing rests on...
Back in those days a screen was often 640x480 = 307 200 pixels
An iPhone 12 Mini has a 1080×2340 screen = 2 527 200 pixels = over 8 times the size of those old screens
Today's OS:es work with much much larger datasets overall, not just in graphics but elsewhere as well, and are optimized for that