I disagree, because industrialized gambling is very different from illegal gambling in terms of availability. I see the prevalence of slots in my neighborhood after they legalized gambling wholesale in my state and I don't think it's been made better by "regulation" except through some additional taxes, it's just made it easier to access.

The same could be said about prohibition for alcohol and tobacco. Raising the age for legal tobacco consumption did reduce consumption, and prohibition did lower consumption permanently for alcohol.