Why is it that in British sitcoms everyone is poor and for Americans its the opposite?

Am I the only one who believes this, like in British sitcoms from
recent to the ones going back decades, like On The Buses, Are You
Being Served, Man About The House, everybody seems to have a job but
they live in share houses and dont have cars, they are always eating
basic cheap stuff like sausage and mash and complaining that they cant
afford bus fare or to go on a holiday or a night out, but American
sitcoms are just the opposite, many characters often seem to be
unemployed but they always have a nice modern house or apartment and a
car and they are always going out to eat at restaurants and money is
never mentioned, notably shows like Seinfeld and Friends.