Cities are much more tightly tied to their team in European sports, generally with a level of ownership stake. In America it’s a business. Always has been. And really they just follow the path of big business. Plenty of businesses make cities bid for their favors. Scarcity has a lot to do with it too. With 32 teams, 50 states, and arguably about 100 cities that could support a team, there’s always somebody saying “come over here”. That being said, things have actually been pretty stable for a long time in the NFL, that was going to end eventually. Predict the Chargers and Raiders will move in the next 5 years, then things will calm down again.
Time to expand NFL to 40 teams.