Also, I just clicked on the most recent conference on clojure.org : https://clojured.de/schedule/ , and there is a talk mentioning monads while promising to not talk about monads :-D So it kind of reinforce my point that basic theoretical concepts are silently everywhere ^^ (and fully not necessary for almost everything).

But I don't think conferences are representative of the "on the ground production experience" that you have, or at least can have.

I personnaly wouldn't submit a paper to a conference with a talk "Here's how I made a whole backend stack using boring scala, and it just works" because as you say, I feel it's just full of theoretical speakers and that wouldn't interest anyone. Meanwhile, I also did code a whole backend in boring scala, and it in fact just works, and it feels good :-)