Microsoft went public for a valuation of around $300M and is trading over a $1T now. This means that regular investors had a chance at all this growth.
Newer companies like AirBNB and Uber went public at what could be their max market cap valuation of billions so investors wont' get much of a chance to make money from these companies.
In addition to this problem of private investors(VC's) taking most of the profits, we now have such concentration of wealth that the big PE firms can buy alot of what used to be small businesses and roll them up.
Vet clinics, medial practices, engineering firms, etc all use to to thrive on being 20 person shops are now routinely being bought up by PE firms and rolled into larger companies which means far fewer entrepreneurs or chances for up and coming employees to buy into the firm from the founders, which helps stall careers.
Heck you see it now with these firms buying up single family housing in US cities now and then renting them back to people, transforming regular middle class people from home owners to renters, and transferring the home appreciate from the middle and lower class to the PE limited partners ensuring the rich get richer and the middle class disappears even faster.