Huh? My team isn’t pushing the state of the art by any means, and I have about 6 guys running about 40k hosts globally and they are more secure, better configured, etc than the work I did 20 years ago. Then, I worked with a few hundred Unix systems as part of a team of like 40.

Systems and storage has advanced significantly.

Computer science may be stagnant, but practical applications of topics researched decades ago has flourished from small seeds into large forests.

I am pretty sure that all research on stuff we are since the horizontal scaling has taken over have been researched 4+ decades ago and is only now is widely used... though when I looked, the CAP theorem is from 1998, so maybe not.

The fish rots from the top. Lobbyists in the policy sausage making machine are likely the blame for the stagnation. The iPhone's introduction brought back to life the results of past research in industry. For example, Gorilla glass. And, compare the rocket engine design of SpaceX's Raptor, BO's and the designed to be reusable but to be thrown away after single use SLS's.

Neither aeronautics nor material science have stagnated. I doubt computer science has either.

You're clearly unaware of research on programmable matter!