The triplet code--the most fundamental aspect of understanding how life could work on a day-to-day basis instead of just being chemistry with peculiar polymers--was discovered in 1961.

Hodgkin and Huxley discovered the basic principles of how neurons work--essential for understanding the mechanistic basis of pretty much all human and animal behavior--in 1952.

The correct conception of plate tectonics (not the mechanism-free "continental drift" that was correct only by accident, not via physics) was worked out in the 1960s--without which it is practically impossible to understand the geological history of the Earth.

These are huge shifts in our understanding of the nature of reality and the world we inhabit that occurred far less than 100 years ago.

And this isn't counting the numerous major advancements that aren't quite as dramatic of shifts as, say, the discovery/formulation of Maxwell's Equations.

There's no grinding to a halt. We just have stopped being clueless about some of the most basic areas of reality, so it takes a little longer to find the others and/or the advance doesn't turn everything upside-down because we already turned it the right way up. Maybe Thomas Kuhn would be disappointed, but you can get an extremely long way with incremental science, and we've incremented a lot.