You're comparing legal to illegal. That's kinda moving the goal posts a bit. By definition illegal things are things society as a whole have declared impermiss

You're comparing legal to illegal. That's kinda moving the goal posts a bit. By definition illegal things are things society as a whole have declared impermissible. By contrast cigarettes and advertising are legal, meaning that society has determined them to have value. Not surprisingly illegal things still happen because there is still demand by some minority for that service. Society as s whole though has decided that the negative effect on others outweighs the positive effect on the few.