"provide for their needs"...? What do you mean? Sure, many gamblers don't have a very stable economic situation, but you're implying that something like UBI would suddenly stop people from gambling or what?

And then there are those of us for whom gambling is not a need. And I think it's problematic to regard any unnecessary activity, especially one that's a known focus for self-destructively compulsive behavior, as a need.

Heroin's a pressing need too, when you're addicted.

Well what is the difference? A vice is a vice. Both are used to distracte us from the daily life of contant reminder that we are just a flesh bag being controlled by a mass of fat that will decay and die at some point. While we circle around a massive black hole. So why is this one vice so different that you think that prohibition would work?