I think your points are pretty spot on - most things have already been invented, and there's too much of a move-fast-and-break-things mentality.

Here's a follow-up thought: to what extent did the grey-beards let us juniors down by steering us down a different path? A few instances:

DB creators knew about replicated logs, but we got given DBs, not replicated log products.

The Java creators knew about immutability: "I would use an immutable whenever I can." [James Gosling, 1] but it was years later when someone else provided us with pcollections/javaslang/vavr. And they're still far from widespread, and nowhere near the standard library.

Brendan Eich supposedly wanted to put Scheme into browsers, but his superiors had him make JS instead.

What other stuff have we been missing out on?

[1] https://www.artima.com/articles/james-gosling-on-java-may-20...