Functionally more like parimutuel bets, then? I don’t gamble (on sports or anything else), so I haven’t paid these much attention (though the nonstop betting ads have made watching pro sports much less pleasant).
It's a bit of a conspiracy, but ultimately there is more money in sports betting than in the sport itself, and thus eventually the money will win and sports will just be a mechanism for gambling. The leagues will ultimately be controlled by those who run the gambling and have more money and power than the league itself.
One of the underappreciated concepts behind vice laws is that they function to prevent large-scale coopting of entire industries this way. In theory, at least.