But a much easier argument against sports betting is that it ruins the sports. Players throw. They get good at subtly cheating. The gambling apparatus latches itself to the sport, to the teams and players, the umpires and judges, the sporting organizations. With this much money on the line, it's not a matter of if but when games are thrown, cheated -- the bigger the game, the bigger the incentive. It's even easier now because of the amount of side/parlay betting that is available. It exhausts the spirit of competition.
Sports gambling is diametrically opposed to sport itself.
There's a false dichotomy between prohibition and laissez-faire, which the US seems particularly prone to. You've seen similar issues with the decriminalisation of cannabis, where many states seem to have switched abruptly from criminalisation to a fully-fledged commercial market. There is a broad spectrum of other options in between those points that tend to be under-discussed.
You can ban gambling advertising, as Italy did in 2019. You can set limits on maximum stakes or impose regulations to make gambling products less attractive to new customers and less risky for problem gamblers. You can have a single state-controlled parimutuel operator. Gambling does cause harm - whether it's legal or not - but it is within the purview of legislators to create a gambling market in which harm reduction is the main priority.
One regulation would be banning gambling advertising, for the same reason why smoking ads are (I think?) banned. It is especially nefarious how companies lure in new customers with free bets, often with unscrupulous cash-out conditions, in order to get people hooked. It’s the equivalent of ads providing someone a coupon code to get several boxes of free cigarettes, at which point they get hooked.
Another change I’d like to see is the end of mobile gambling. I’ve never done it, but from watching friends do it, it was far too easy to deposit money, or borrow money on credit, and bet it frivolously. At least if such behavior is confined to a casino, there is some larger barrier to entry for people.
I do not know if this is true in other states, but certain states have the ability for an individual to self-institute a gambling ban at all facilities in the state. I’m not sure if this applies to gambling online. If not, then it should. And if other states don’t have it, then they would greatly benefit from it.
It also seems somewhat fair to me to tax the casinos and other companies profiting from gambling and using that money to fund services for people who become addicted. If you’re going to help create a problem, you should have to help clean it up.