Win98 was head and shoulders above System 9, from a stability perspective. It had protected memory, actual preemptive multitasking, a somewhat functional driver system built on top of an actual HAL, functional networking, etc, etc.
To be clear, Win98 was a garbage fire of an OS (when it came to stability); which makes it so much worse that Mac OS 8-9 were so bad.
98's multitasking and memory 'protection' were a joke. In the same mid high machine for the era, 2k and xp were miles ahead of w98 on mid-high load.
Maybe not on a Pentium, but once you hit 192MB of RAM and some 500 MHz P3/AMD k7, NT based OSes were tons better.
You only realized that upon opening a dozen of IE windows. W98, even SE, will sweat. 2k will fly.
On single tasks, such as near realtime multimedia ones, w98 would be better, such as emulators/games or video players with single thread decoders. On multiprocessing/threading, w98 crawled against W2K even under p4's and 256MB of RAM.
Well, Win NT is an actual operating system, and Win 98 and Classic macOS are just horribly overgrown home computer shells in an environment they should never have been exposed to.
Ahem, w98 BSOD if you sneezed hard near it. Installing a driver? BSOD. IE page fault? BSOD. 128k stack limit reached? either grind to a halt or a BSOD. And so on...
I worked at a company that was delivering a client-side app in Java launched from IE. I think we had an ActiveX plugin as the "launcher." This predated "Java Web Start." It was hysterically bad. We were targeting 32 meg Win 98 systems and they were comically slow and unstable. Most of our developers had 64 and 128 meg boxes with NT 4.0. I mostly worked on the server side stuff, and used them as a terminal into the Solaris and Linux systems.
To be clear, Win98 was a garbage fire of an OS (when it came to stability); which makes it so much worse that Mac OS 8-9 were so bad.