Amiga at least, older computers were more responsive because they did less - directly attached video and keyboard hardware, no USB, no compositing video drivers

Amiga at least, older computers were more responsive because they did less - directly attached video and keyboard hardware, no USB, no compositing video drivers, less font smoothing, and so on. See Dan Luu's analysis here: https://danluu.com/input-lag/ https://danluu.com/input-lag/ and here https://danluu.com/keyboard-latency/ https://danluu.com/keyboard-latency/ > Moreover, a modern computer with one of the slower keyboards attached can’t possibly be as responsive as a quick machine from the 70s or 80s because the keyboard alone is slower than the entire response pipeline of some older computers. Haiku (BeOS) was always promoted on its native multithreading and responsive UI, with early demonstrations showing windows being dragged around while playing video, IIRC, it's impressive that it still holds to that. But it also says a bit about what software people pay for and keep using - if sluggish Windows software has thrived, and BeOS crashed and burned. And then on Windows and Linux, light fast software gives way to bloaty huge sluggish software left and right.