It helps the pro gambling states next to the ones who ban it. I’m from SW Louisiana not far from Texas where there are several casinos. Most of the people who go there are Texans and taxes on those casinos pretty much funded my education :)
Gamblers are going to gamble, all Texas is doing is sending its money out of state.
Getting the state involved in gambling is a bad, bad thing. Texas is better off on it’s balance sheet by keeping it out of TX.
And you are right, that gamblers are going to gamble. They are free to do so in OK or LA.