A lot of them are using obscure vocabulary and sciency notation to express very basic ideas. It's like some switch comes on "this is a PAPER it needs fancy words!"

I'd actually like a change from the other end. Instead of "make agents so good they can implement complex papers", how any "write paper so plainly that current agents can implement reproduction"?

Scientific vocabulary is designed to be precise. The reason papers are written the way they are is to try to convey ideas with as little chance of misinterpretation as possible. It is maddeningly difficult to do that - I can't tell you how many times I've gotten paper and grant reviews where I cannot fathom how Reviewer 2 (and it's ALWAYS Reviewer 2) managed to twist what I wrote into what they thought I wrote. Almost every time you see something that seems needlessly precise and finicky, it's probably in response to a reviewer's comment, and the secret subtext is "There - now it's so over specified even a rabid wildebeest, or YOU, dear reviewer, couldn't misundertand it!" Unfortunately, a side effect of that is that a lot of the writing ends up seeming needlessly dense.