The gatekeeper idea you mention is one of these elements that I feel is self-reinforcing. Despite filmmaking equipment getting progressively cheaper, even indie budgets are growing, & the whole industry is getting more and more insular, with low acceptance for spec scripts & a lot of big-budget low-risk franchise flicks. From the 70s straight through the 90s, even though film cameras were an expensive specialty item & editing equipment was difficult to use & to afford, we had people dropping lots of money trying to make (mostly awful) films. Today, when it’s possible for someone in the lower middle class in the west to make a feature length film with only the phone & the computer they already have (paying nothing for software), we still have big-budget theoretically-indie youtube channels, rather than an explosion in amateur narrative films.
I used to run something called the “No Budget Film Contest”. We’d take submissions of films, rank them, & give small (less than $10) cash prizes to the top 3. For a film to be eligible, the creator of the film could not have paid for anything specifically for the film, with the exception of camera rental — no paid actors, no set pieces or props, no expensive editing software. The goal was to demonstrate that one could make reasonably interesting movies using no resource other than time: in other words, that small scale productions can be valuable, and that you don’t need to get studio involvement or a successful kickstarter to make a film. It’s been a while since I hosted one of those, but it might be time again.