In terms of use, definitely; the advantage to legalization is on the supply end, where law-abiding sellers can now outcompete the criminals and drive them from the market (if the former aren't hobbled by excessive taxes and regulation).
Cannabis smoking 'permanently lowers IQ'
50% of the population have a higher IQ than an 18 year old with an average 100 IQ. If he vapes 3 times a week for 20 years, by age 38, he will have suffered an irretrievable 8 point loss in IQ down to 92, so that 78% of the populace have superior intelligence to him.