You're equating loss of payroll to the ONLY item that would be lost by the Brewers leaving, which is factually incorrect. As noted, a study independently calculated the revenue associated with the stadium over it's first 19 years at 2.5 billion, which is a pretty hefty return on investment. Extrapolated over another 13-year extended lease period, they'll get back more than $290 million.
I know, you'll cite this as a benefits-only analysis, but that it is benefits-only doesn't mean the resulting data is incorrect. Nowhere was the study intending to show the results relative to another investment- just, literally, the resulting benefits of the actual investment made. Sure, the state could have had a better return if they had taken the stadium costs, put it all on 7 on the roulette wheel at Potawatomi and had it hit, but the actual resulting 'benefit' return on the stadium is relevant to the discussion, and highlights that simplifying the necessary return to breakeven down to state income tax on the teams' payroll isn't fair at all.