Maybe my travel is more complicated but I even not infrequently get annoyed with "past me" for various travel-related decisions. I avoid red-eyes but at some price point I won't--or maybe only if it's someone else's money. And maybe I don't have a choice based on my schedule or just what flights are available. Normally I won't do an unnecessary layover but maybe I will to fly my preferred airline.

It gets complicated in a hurry and for the cases where it is relatively simple (and when it gets into very complex international travel a voice interface is going to be completely useless), I can look up my options pretty quickly on a computer.