I wouldn’t go quite that far but yeah, in my view there have only been a handful of main paradigm shifting changes; Language, fire, tools, husbandry, agriculture, metallurgy, electricity.

The primary separation between humans and pretty much everything else on earth is the passing of knowledge from generation to generation so if I had to pick the innovation I would probably pick language.

I’m not sure if we are talking past each other this point or what, but take the Internet since you mentioned it;

Let’s compare to transistors for instance. You could have (and did have) the internet without transistors and you could have transistors without the internet. Nobody would argue that either are not massively impactful inventions but neither would exist without electricity. Electricity is the paradigm shifting breakthrough. In the same way neither cannons nor guns were the breakthrough themselves.

…but the pace of iterations seems to be slowing down.

I thought that was the whole conversation we were having. My main point was not only that innovation is slowing down but that we should expect it to slow based on the trajectory of previous paradigm shifting breakthroughs.

… all building on what came before.

That was my point though. Metallurgy gave way to cannons and guns but we don’t have a “cannons and guns” age. Everything is iterative but occasionally we have something come along that changes everything and starts the iterations anew. But that has never continued after, just been followed by more iteration.

Also, it took over 1000 years to get from the first steam experiments to a useful engine.

Isn’t it though? Each age has had its technological advance that defines that age. But at no time did the next age come immediately. It was always reasonable to assume that after electricity there would be yet another lull before the next paradigm shifting innovation. It seems to me that the great lie of capitalism has been convincing people that every new product is that next great innovation.