I recently bought an Apple MacBook air with a M1 chip and only now has my system a similar performance as my Pentium 4 with BeOS used to have almost 20 years ago!
Cleaner designs that just seemed better at actually making use of the available hardware, even though it was a single core Pentium 3 (or my parents older first gen Pentium).
I often ponder how things would've been different if something more like them had taken off and become mainstream.
IIRC, as it relates to BeOS, Apple was going to acquire BeOS or NeXT and opted for NeXT.
If Apple had gone with BeOS, the computing world would probably be a very different place today, given all the great things Apple did after Steve Jobs came back.
An alternate reality where Apple acquires BeOS over NeXT does make for an interesting "what if" story though.
The BeOS C++ api was nice to work with, and every little thing was a thread. I think if it became more mainstream we might have had a higher core-count.
I wrote a simple windows implemention of the BApplication and BWindow etc. classes, which allowed me to compile to two platforms :-) I was very interested in OSes at the time, and ran BeOS at my job at DeltaKabel / Lucent
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).