I always hear people say this as a ‘gotcha’ but it doesn’t make any sense.

I have travelled while homeless.

People will be renting an apartment in a developed city, owning a car, going out to pubs/nightclubs, and then telling dirty backpackers, “God must be nice to have the money to travel!”

travel vs sedentism, neither one is necessarily more cheap/expensive than the other

You could have posted this as a top-level reply to the question…

Inconceivaballs

That was not the first film adapatation

Science-fiction comedy