The market grows because people are want to participate in it. See crypto currency. Thats a market that grew with no corporate planning, simply from people increasingly participating. Many people think they should have exposure to markets they don’t fully understand and automatically have a portion of their pay go to such investments made on their behalf, be it crypto or a more ‘grown up’ seeming fund.

Well, lots of crypto grows on the same way that any pyramid scheme grows: they hope there will be many greater fools who will buy in so they can cash out. I don't think that's equivalent to the S&P500's growth over the last 100 years.