That’s totally true but if it is legal there will be more users and people driving under the influence. Drinking under the influence of alcohol statistically drops in states where marijuana is legal according to some sources. One could say it’s reasonable to expect that some drinkers are replacing alcohol with marijuana and driving under the influence of that, in addition to the people who already drive under the influence and the new users who will drive under the influence because it’s already socially acceptable among people who smoke marijuana who genuinely believe (falsely) that they drive safer while smoking/under the influence of weed. https://www.webmd.com/mental-health/addiction/news/20220113/more-folks-drive-high-when-pot-made-legal-study