I had read how, when the 68000 came out originally, it was considered to be a "minicomputer on a chip", while the 68030 was anticipated to be a "mainframe on a chip".
So, I was unable to viscerally appreciate that perspective, until I ran the original MacPaint, which was extremely optimized for the 8MHz 68000 in the original Mac, and then I was amazed at how fast the 68030 was.
I had the Amiga, 68000 at 7.09 MHz (PAL, NTSC ran a teeny bit faster). Both Mac and Amiga gave fully featured, incredibly low latency GUIs. They might think a bit after the click, but compared to a modern GUI, oh so snappy.
Windows, OSX, X with whatever Windowing never get close to that instant tip of your fingers response. I miss low latency responses.
The Mac mouse pointer was always responsive due to interrupts, but that didn't mean that what you clicked on was.
However, the thing that I hate most about the modern web and similar UIs is that they reflow or otherwise move the content you are looking at after you click and before the click is mapped to an element, so you don't get what you click or tap on. This is absolutely unforgivable in my opinion, and absolutely not a matter of degree or grey areas unlike most of the things people complain about.
Took years after I abandoned the platform for serious use for Windows not to always be more sluggish, and get dramatically worse when under load. Course by then I was on '040 comparing with Pentium something.
Also images were much, much smaller, both in terms of pixels and amount of compression applied, using large images that weren't content was heavily discouraged, and no-one used auto playing videos. To the extent that sins against bandwidth were committed it was mostly with Flash, which we all complained about and which is now reviled, but which was in fact generally way less abusive, confusing, and performance-destroying, than what gets done now in the name of "modern UX". Pages were much smaller, devs were much more sensitive to markup bloat. The worst we had on that front were WYSYWG-made pages (Frontpage, for example) but they've got nothing on the kind of attribute bloat and huge JS payloads one sees now (and the JS in particular can keep on allocating memory after its text is loaded into memory then parsed into even more memory, with predictable results on resource use and page load times)