> To take the other side, my understanding is in the US there aren't any "second division" teams. You've got 350 million people and about 30 professional American football teams, or 10 million people per team

There are - but popularity is vastly different. My understanding is that minor league baseball has a notable following, basketball is smaller but there are still some passionate fans, and that football is mostly "keeping players warm".

There's also the "D1 College" as a "second division" of sorts.