I remember the Apollo reps moaning that the speed of Motorola's 68k chips weren't keeping up the the x86. I still have an Apollo motheroard with two 68k chips on it -- a work around to enable virtual memory.
Yet Domain OS was a distributed multiuser and multitasking system, with BSD and SYSV compatibility which run decent on 1989 hardware when x86 was almost only DOS and Windows 3.
But did it do the things people wanted? Why have the complexity of a multiuser system on a single user PC? Why have multitasking when the system can barely run a single task competently?