That's the kind of thinking that leads to janky APIs. When you say "just" you're doing the same thing the LLM does - you're removing all the nuance and complexity from the activity.

For example, your concept of an API as just a set of functions does not consider how the API changes over time. Library authors who take this into account will have a better time evolving the library API. Library authors who don't might write themselves into a corner, which might force some sort of API version schism which causes half the API to be nice while the other half has questionable decisions, causing perpetual confusion and frustration with users for decades.

The LLM hallucinating some nice looking function calls doesn't really take any of that into account.