That might be the best solution to gambling. At least in Canada, casinos are very well advertised and glamorized. They're often run by the government, but they still market themselves to attract customers in a way you wouldn't expect of say, a safe opioid consumption site. Their slot machines are just as addictive. Sure, there's lip service paid to preventing gambling addiction, eg a piece of paper on the wall instructing patrons to play responsibly. But if we took the same attitude towards it as we do to tobacco, it might just fade away without all the downsides of prohibition.