Tbh I often use it to get a starting point. If you ask it about say martial law it'd likely mention the main pieces of legislation that cover it which you can then turn to.
Even if it does that early on you'd just land on unrelated legislation. You'd notice pretty quick that it's about a whole different topic.
The reason I do it in combination with normal search is that normal search will often get clogged up by 3rd party websites and at best lead you to only the main legislation. The LLM is likely to name you the main legislation so you can search for it directly by name and also mention other major related pieces.