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.