I've got a G3 iMac running macOS 9.2 that I recently restored sitting on my desk. Of course it's a lot of fun to play the old games but even browsing through applications, sifting through menus, and playing with the old UI patterns is just so refreshing. It's technically slow but latency feels so much better than modern machines.

Sure, the OS is technically inferior, and an infinite loop can freeze the entire machine, and my goodness that filesystem with all the goofy metadata is infuriating. There are all sorts of hidden resource metadata on each file that makes even program to file association bonkers. But otherwise there's a lot I like about it and a lot it gets right compared to modern operating systems. Older operating systems are just such a thin layer on top of the machine, compared to the mountains of abstractions and complexities of modern operating systems.