I agree. The core fundamental concepts and abstractions are relatively stable (most innovation seems to be happening in the Haskell/FP camp), as well as the programming languages being used. Even the newer widely-used languages (Javascript, Python, etc.) are old by now.

What changes are lot are the actual frameworks and libraries. E.g., while Java is twenty years old now, Hadoop, JAX-RS, Hibernate, etc. did not exist then. And while Java will probably still be in wide use in twenty years, those libraries and frameworks will have been replaced except in legacy code.

I think the only 'platform' that has been stable for ever is UNIX. People are still using libc, POSIX (ok, SUS), etc.