The point of any crackdown on gambling is to reduce revenue for what are considered to be bad actors. The size of the market might be a factor for politicians when considering how much revenue to try to reduce the industry by, but law makers continue to prove over and over again they aren't necessarily that smart once they believe their constituents are panicking about "think of the children!"

Admittedly yes, destroying an entire industry that large would be an absolute worst-case scenario you would hope politicians are smart enough to avoid, I don't think it "likely" but I do find it useful to consider how far it could go, because it happened once (to Pinball), and we shouldn't forget that.

(ETA: Keep in mind that gambling laws in the US are extremely local with sometimes even cities in the same state disagreeing, and if a panic happens you just need a few localities with dumbest politicians to pass the harshest bills, and others to copy cat it at "public demand". That's how it happened to Pinball. That's how it happens for all sorts of terrible laws in the last few years we could point to. Bad laws in a panic are viral in the worst ways.)