Widespread gambling is one of the most visible symptoms of a corrupted society. A society that chooses to make gambling frictionless is a society that has given up on pursuing higher virtue. There are no significant positive externalities and it is functionally just a wealth redistribution to the people who have no problem hurting bystanders to make a bigger problem for itself. Gambling does not just impact individual gamblers. People who gamble their resources away must then either rely on friends, family or the state to get by. We all pay for this directly or indirectly.

And the societal value is...it's fun? Even that I push back on because gambling interferes with your relationship with the event. Once you place a bet, you are literally invested in the outcome. On the one hand, yes, of course this enhances the felt outcome of victory if your bet pays off. On the other, it closes you off to enjoying whatever happens on its own terms. The home team often loses so you need to find away to enjoy the experience even if the outcome isn't what you hoped for. This allows you to actually appreciate the players on both sides and enjoy the competition for what it always actually is: an exhibition of human skill, enjoyable on its own terms (or not, if you aren't interested in that particular skill).

Gambling also brings the worst kind of people into your community. Both producers and consumers. The gamblers do not actually value the event and the operators want to distract you from the event and turn you into a gambler. I have written off the nba, which I used to greatly enjoy, because of the faustian bargain they have made with the sports gambling companies.