Bottom line: Nobody watches NFL on TV, Nobody attends any NFL games, Nobody buys anything for clothing, NFL would be gone quicker than you think. Local politicians give all the incentives because of the revenue a team brings to the city - - - by the fans.
The fans that attend local pro sport events, are for the most part local folks that would spend their disposable income locally anyway.
Pro sports bring large incomes to two groups. 1) Pro sport team owners. 2) Pro sport team players and coaches.