Season 1s are great, setup, some payoff, a bit of lead into the overarching story. Then season 2 to X. The heroes win and then lose in the final episode, cliffhanger to next season. People get bored. Final season is announced and they wrap up the show.
I love the limited scope of British TV series. They even managed to do only a few seasons of Law & Order, for crying out loud.
It’s not a creative or artistic choice; British channels simply have minuscule budgets compared to their American counterparts.
And yet it often leads to more satisfying narratives.
Look at Black Mirror. The British seasons are some of the best TV ever made. The American (Netflix) seasons have often been meh or downright awful, and derivative of the original seasons.
I think it’s for the best. Too much money in the US is spent on bullshit.
In any case, US versions of British series are almost certainly worse.