Honestly just doing a Google search about what you want to do makes a page from this website appear, and it is usually very detailed while having a small "quiz" at the start to filter the information based on your situation. It's not just for life events, but for basically any public French administrative work. You'll have pages about your car, about your job, or if you want to immigrate, and so on.

At the bottom you also have other relevant links (usually to the website of the specific administrations of what you want to do) including reference to the current law that the page is based on (https://legifrance.gouv.fr is also great)

For what I used it for, it was never ambiguous in determining your situation

As far as I can tell, the america.gov LLM is mostly providing links to the landing pages you would have found through classical web search. Perhaps with a little bit of clarifying information when there are multiple choices.

Honestly, using an LLM the way america.gov does it, is pretty much the same thing as using search engines, except the result you wanted is almost always in the first result, not 2/3 of the way down the 4th page. Or 42nd on a list of things you are not interested in at all. So much more efficient!