> Domestic flights in the US are like busses/trains elsewhere. Most people fly without a checked bag

That sounds like bullshit to me.

Most domestic flights are short duration trips, a week's worth of clothes fit in carry-on suitcase, and the other stuff (laptop etc) can go in a backpack.

In all my domestic flights in the past year they've had to ask people at the gate to volunteer their carry-on suitcase to be checked into the hold because they didn't expect to have enough room in the overhead bins.

I usually volunteer because: it's free, I don't mind waiting at the pickup, and it's slightly more comfortable when getting off the plane.

I don't know if we are the level of "most people" but I'd say we are defintely at a "signficant percentage of ppl". Due to cost of checked luggage the popularity of one bag carry on flying has exploded.

> That sounds like bullshit to me.

Have you taken a US domestic flight? Everyone wants to bring their massive roll-ons into the cabin, nobody wants to check if they can avoid it.