I think because 90s which is far more interesting is continuum. PC is partially backwards compatible over decades. Thus it is hard to isolate any single segment

I think because 90s which is far more interesting is continuum. PC is partially backwards compatible over decades. Thus it is hard to isolate any single segment unlike "8bits" which were mostly one and done. You can get some points like end of DOS beginning of Windows 95/98. But there after it kinda blurs. Tech got better and old stuff kept mostly working. So you really cannot just stuck yourself in singular point. Not that there isn't opportunities like peak of DOS gaming with Gravis Ultra Sound and some Sound Blaster. Or early 3d gaming.