I think there is just too much faith from the current crop of investors in tech start ups, many got hurt in the past by not investing in things after not getting good answers to “ok but how does this make money” or “can this actually do what you’re claiming”.
And larger more established companies like Google and Amazon are happy to feed the hype for a lot of these trends, particularly when all the new start ups are going to be buying stuff from them, so even if the start ups fail because they can’t make money or don’t do what they claim, the big companies still made money selling them server space, computing time, or huge amounts of data. I think investors who hold stakes in the big companies also lean in to the hype for this reason.
Everyone has a pretty good incentive to lean in to the hype, so they do.