I don't think "new libraries and languages, ... won't gain traction". I think that a higher standard is expected for a new library or language to gain traction.

I foresee the entire "technology adoption lifecycle" of innovators, early adopters, early majority, late majority, and laggards will be longer due to the relatively higher expense of adopting a new technology. I don't think it is a bad thing, but it might delay the adoption of promising tech in industries.

Meaningful library/language improvements will have their benefits, regardless if the user is a human or an LLM. Therefore, their adoption will see benefits as well, eventually.