Not sure about total death rates but I think gambling addiction has the highest suicide rate of any of the big addictions out there. It seems truly ruinous. I suppose if any random person can blow their savings on out of the money options theyre unable to gauge the risk of then they might as well be allowed to do the same with crazy parlay bets but seeing the whole landscape of sports betting evolve over the last handful of years has still been quite eerie to me.
My gut these days tells me its probably better for the humans in society if this stuff is left only to black markets because it seems like it destroys lives.