You hit the nail on the head and this is exactly why these things get funded with taxpayer dollars.
They point to the revenue and tax dollars a large enterprise generates. If the Sox leave the city we won't have those dollars to fund the stuff that directly benefits the average resident. Or with this stadium the city will have all these extra dollars to spend on projects everyone wants.
The projections always seem grossly optimistic but it's painted as an investment. Would you spend $10,000 in 2024 to make and extra $30,000 over the next five years?