I'm curious, the article talks about the issue where a small number of, essentially, addicts, are responsible for a huge portion of total sales (10% of players are responsible for 2/3 of total revenue). I find this interesting because this pattern repeats in a number of different "potentially addictive" pursuits, where the pursuit can be a pleasant and welcome diversion when done in moderation, but is ruinous for add…
Consider where lotteries come from - everyone in the room puts their name in the hat and then one winner is drawn (or maybe also a 2nd prize and 3rd prize). But it's simple - 1 person, 1 chance.
You just can't buy more in that system. So the 'problem gambler' that blows most of their paycheck on lottery tickets just isn't even possible.
Maybe the limit doesn't need to be strictly 1, but even just having a limit, low enough to not be too much of a hardship even to a poverty-level person, would still be a simple solution.
People sure wouldn't like it though.
They'd immediately start working on ways to get around that limit. Same as they would if you limited them to only buying 1 6-pack of beer per week.