They're also in geographically low population areas so counting them and the people employeed in their towns they have a significant sway on some states and the Senate skews things towards low population states through it's inequitable representation AND the outsized power Senate rules give individual Senators.
Plus it's made a few people EXTREMELY rich so they've made their opinions and interests everyone elses problem too.
Every once in a while someone in the Netherlands argues for the district system and they are immediately shut down with "America".
One man one vote. And yes the regions that contribute more to the economy are a priority. They fund everything including the military without which we'd still be a part of Spain.
Yeah I get the idea originally, you had to appease the slave and smaller states to get them to join the plan originally at all, but there's a very, very good reason wherever the US has had the chance to design a new government we have never saddled them with our system. I don't think there's a reasonable hope that it'll get reformed in a clean way though.
Plus it's made a few people EXTREMELY rich so they've made their opinions and interests everyone elses problem too.