iOS is the only remotely-mainstream GUI OS I know of that feels similar to BeOS, in terms of responsiveness to user interaction, though I'd say that's less true

iOS is the only remotely-mainstream GUI OS I know of that feels similar to BeOS, in terms of responsiveness to user interaction, though I'd say that's less true now than it was several versions ago, even on very new devices. 3-6, and the hardware those versions ran on at release, seemed like the sweet spot for magically-instant responsiveness to input. Agreed that M1s with macOS have temporarily given something kinda resembling that back to the desktop, though I'm sure developers are toiling even now to make sure it feels slow a year or two from now (mostly not developers at Apple, to be clear).