You’re not being realistic if you think removing the stigma of illegality from marijuana won’t lead to much more widespread use. It will, and it has in those states that have legalized it. There are downsides to marijuana, I’ve lived it. That doesn’t make it an entirely bad thing but you’re fooling yourself if you think it’s an entirely good thing. You can’t tell me that smoking marijuana isn’t going to lead to lung disease just like cigarettes. Additionally there are psychological impacts from marijuana usage in a not-insignificant number of users. Behavioral changes, it’s a mild psychoactive with moderate use. With heavy use it’s not so mild. Preexisting psychological disorders will be aggravated, the nuts will get nuttier and the undiagnosed ones will come to the fore.
And then my tax dollars will go to support these chronically unemployable users.
I do know some people in legal states who had not used pot for many years who have now started again and find it helps with fatigue and the aches and pains of getting old. One person grows their own and makes a tincture with grain alcohol or vodka and puts 1/2 a teaspoon in their morning coffee. They don’t drive their car to run in city errands until late in the day by which time little effect remains. Another older person uses the tincture by putting 2 or 3 drops in a beverage 4 or 5 times a day. I have no information on what young people are doing other than not being jailed as often for small quantities. Regarding lung health, there seems to be little or no bad effects of MJ smoking over time as a number of links I read report, see below. Everyone I know supports or practices moderate use. I do not use, but might if I had constant aches and pains.
https://www.alternet.org/drugs/what-are-risks-marijuana-smoke-compared-tobacco