There are guardrails. Gambling is legalised to introduce guardrails so that regulated providers can exist and provide a product that stops people using offshore.
Neither accessibility or advertising impacts rates of addiction. It is a real addiction. Does a lack of advertising stop heroin use? Behave.
So the number of smoking addicts magically went down over the last few decades?
If advertising didn’t work to drive consumption no business would ever spend a dime on it. When your product has addictive qualities advertising absolutely increases the number of people that get hooked. This is something that was well understood in the past, for example the huge curtailment in cigarette advertising.
I want to chime in not necessarily to disagree but there is a lot of unknowns in how effective advertising really is and in a lot of cases, if it is at all.
Additionally, the curtailment of cigarette advertising wasn't because it was understood to be bad, it was because a bunch of politicians found it to be politically beneficial to "do something" so they threw everything at the wall. Increased taxes, counter advertisement, advertising bans, smoking bans in certain places, required packaging, etc. Who knows what actually worked, if any of it did.
We're seeing a big decline in alcohol consumption right now in younger generations right now and none of those things were done to cause it.