Motorola 68k was really fashionable for a while in the 1980s but then Motorola gave up on it and everybody who was dependent on it either went out of business or switched to RISC architecture.

For some reason, nobody outside the PC world was interested in the 386. When Apple was struggling throughout the 1990s there was always the rumor circulating that Apple had developed a 386 version of Classic MacOS but it never saw the light of day. For one thing a company like Sun Microsystems or Apple that specializes in making computers that are much more expensive than PCs would not want people to get anywhere near the PC clone ecosystem where you can pay less and get a lot more.