To be fair, you can cancel flight reservations for a full refund within 24 hours, so if the LLM gets it wrong, you're not on the hook for anything.

But in general I do agree: flight bookings are something I want to do myself, because even I don't fully know my preferences when it comes to timing and price until I see what's available. And in general I don't find it all that difficult to do. A couple days ago I booked a multi-city travel itinerary with four different destinations, and it took me about a half hour?

Sure, if an LLM can do that in under a minute, that would be cool, but in absolutely zero situations would I not need to check its work, and if it did get it wrong, I'd have to do it all myself anyway.