What Firefox provides here:
A connector to LLM providers.
Accelerators (context menu options).
From a coding perspective, this should ideally be a very lightweight functionality.
This feature is very analogous to options to add a search engine, and also to provide accelerators via context menu.
While it can be done via third-party or Official Mozilla add-ons, but (to me) it still makes sense to have it part of the product.
shh..it's a spyware and adware!