Watching demos, in a way, brought to nerds the same kind of excitement as watching sports did to a mainstream audience.
Much like athletes compete and break records within human limitations (usually segregated by gender, and in some sports weight range categories), the capabilities of specific models of computers were fixed, well-known and each provided a level playing field for a few years to come.
So it was all about technical prowess by hackers for other hackers to appreciate, because the artistic component was still way too weak for a mainstream audience (raster bars or 4k intros wouldn't impress normies much artistically)
Art and creativity started to become more of a thing when capabilities improved to the point where computers could produce graphics and music for anyone to find worthwhile and enjoyable, around the Amiga era I would say.
But that initial driver of technical prowess was changed forever (and possibly died down) with the scene's move to the PC and especially accelerated 3D graphics.
For the same reason that doping ruins the excitement of watching sports, it's hard to be wowed technically anymore because nobody keeps tabs about what PC-of-the-month is capable of. It's a moving platform and there's no level playing field.
This has shifted the focus of the demoscener to creativity / art completely, which is a great thing for art, but at the same time killed what made the demoscene uniquely entertaining for hackers.