Asklemmy

You're not wrong. But there are counter examples. I was going to use the example of the jet engine in my last answer as a true paradigm shifting development that had immediate impact. And in the mid-century period too! Or the first powered flight occurred in the first decade of the 20th century and had an immediate impact. The transistor and solid state electronics would be another example.

So let me flip it around and say we've had a quarter century without a major technological breakthrough. There's been progress, but it feels incremental. I spent a night with a physicist a few years ago who was arguing that progress is slowing because we are still relying on the exploitation of Newtonian physics. There are a few technologies that have made the leap to nuclear physics. But we've had the basics of quantum physics for a century now and haven't been able to exploit it in a useful fashion.

A lot of 3D printing patents from the 80s and 90s expired between 2010-2020, clearing the way for commercial 3d printers and a million innovations. I'd call them honorary 21st century inventions, since the patent holders squandered the technology in the 90s.

https://www.finnegan.com/en/insights/articles/how-patents-die-expiring-3d-printing-patents.html

We had a 3d printer in the 90s at my Uni. It built layers with laser cut paper lol. It was the cheapest version available and it lived in the engineering department for rapid prototyping. This link says they were invented in 1981, metal sintering was added in 1988 and fused filament in 1989. https://ultimaker.com/learn/the-complete-history-of-3d-printing