I don't think that tax revenue would be much. Even if 1000 athletes in the state were paid 100k/year (wildly high number), the state tax of about 7-8% would amount to 7-8 million, which is a pittance.
I think the bigger issues are the loss of the concept of all players in the team being equal (a few are relatively rich now), transfer portal becoming a year-long player trading place (players looking at what bids are coming in for them to make a jump), big donors of smaller schools essentially treating the school team as their own private team (buying the roster, getting couple of stars for ticket sales), etc.
As is typical with professional sports, a few will make lot of money, and the many will just be shuttling between teams for little payments. The question is whether your second-third stringers who provide needed depth will value the UT/UM/UW degree or do they value 10k/year over 4 years from ATM/MSU/WSU.