Why did the Amiga slow to a crawl with lots of overlapping windows?
It seemed to remember hidden portions of windows, which doesn't scale well when you have lots of them.
Why did they use this non-scalable approach to windowing on the Amiga?
👤 compressedgas Accepted Answer ✓
Because applications needed the illusion that they had exclusive control of the frame buffer. Not saving the hidden portion of windows would have required the windowing system to have an incompatible interface as that would require a means of telling the application that it should redraw its window.