I've also thought about this, though not your conclusions.
Pushing society forward tends to require society's help. And a big issue is we've become far less tolerant and more cynical of change. We certainly consider ourselves tolerant but that's mostly on a small subset of all issues - primarily just social stuff like sexuality. By contrast imagine we did not have electric poles up today and somebody suggested we string up these poles all around the country. And they also suggested we wire them up with enough juice flowing through them to kill anything that happened to touch them and something else at the same time - and that these wires could also easily start fires and more. Society wouldn't even consider it - preposterous, unsafe, won't anybody think of the children, blah blah blah. A solar farm frying some birds gets headlines today. I mean... really? Society used to be more tolerant to risk, challenge, and capable of dealing with uncertainty. That opens up the doors of possibility.
Another big change is that I think many peoples' goals in life have changed from moving society forward, to just earning a lot of money. Revolutionary invention is not really the best way to make lots of money in society. In the pure sciences, like physics, it's positively fruitless. Even in the more monetizable fields, it's extremely high risk and the rewards are are wildly variable. 20 years from now Elon Musk could easily be the richest person in history, but he could also just as easily be bankrupt or approaching it. Getting back to the first point, what happens when the first person dies on a SpaceX mission? What if the two people SpaceX plans to send around the moon end up dying catastrophically? It really shouldn't matter in the grand scheme of things, but society would flip a lid, government would try to regulate, and it would be a catastrophe far greater than the loss of life. Dangerous calculus if your life's purpose is money.
Ultimately we have a conservative society that's risk averse and driven by money more than by invention. It's not a good recipe for cooking up revolutionary change.