We're talking about commerce IN the City of Pittsburgh here. Not the burbs, not WV, not Cambria County.
You and your clone can act like the money showing up on gameday is money that would just be spend elsewhere in the city all you want, but you're wrong.
You can keep pretending that all you want. It is simply factually incorrect. Pretty much every economic study not paid for by someone with their hand out has shown it time and time again. I've linked to several of them here just a couple days ago. Stadiums have a near zero net economic effect.