I think it depends on a lot of things, but A P Yu is almost certainly right. A lot of us here analyse things a lot more than 'normal' people booking a flight!

So, *personally* I do think it's a balance between F&B/comfort as much as schedule, speed and cost. And likely sleep quality for a night flight.

But for a lot of people it's either "Direct flight, timing, cost, anything else" (many business fliers?) or "Cost, direct flight, anything else" (most leisure fliers?) I expect. Which sadly does mean the market pushes for more denser, cheaper flights. A lot of people have been conditioned to accept an uncomfortable journey and a "micro-transaction" approach where the flight costs less than public transport to or parking at the airport, and anything beyond a seatbelt costs extra at the time. And there's this feedback loop where that's exactly what the market as a whole is asking for, whether I like it or not :-(