Have you found LLMs to be good at metalinguistic abstraction? I have used them a little bit for lisp programming but never once have I seen them introduce macro.
I explicitly asked LLM to write abstract away with a DSL and it did that. LLMs are good at this too.
I'd imagine they would require some hands-on guidance to create more meaningful abstractions and DSLs for humans.
Call it "vibe coding by tiller". Ha.
Also, I think of metalinguistic abstraction as something deeper than macros. At least not limited to macros:
"An important advantage of making the evaluator accessible as a Lisp program is that we can implement alternative evaluation rules by describing these as modifications to the evaluator program."
https://sarabander.github.io/sicp/html/Chapter-4.xhtml