This is true for older technologies.

Like combustion as you said, we used it a lot and pretty much designed it the best we can with the materials we know and have. But there will be completely new technologies opening up, like maybe fusion. Or solar we know already since a while but made major improvements the last decade and will probably improve it even more.

I was more thinking about how we had this technology rush. I think it is mostly due to the use of fossil fuels and therefore "incredible cheap" energy which also led to humans reproduce a lot. (incredible cheap in quotation marks, because we will probably have to pay the real price which is environmental damage and a modified atmosphere)

When you have a world with 3 times (random number based on nothing) more people you also have 3 times more great artists, scientists, etc. Of course only, if society stays more or less the same. Imagine how many great works we could have if the majority of great minds wasn't preoccupied paying for food and a place to stay like in a hamster wheel.

We already are. There's a reason you don't see intel and amd chips past 5ghz, for example.

Or how modern cars are still functionally the same from 10 years ago just with more spyware and bloat.