What evidence led you to that conclusion? Since alcohol is more addictive than marijuana, more violence-increasing, and the only one of the two that can lead to fatal overdose, I conclude exactly the opposite.
legal restrictions differ as are considered appropriate based on our admittedly imperfect understanding and experience.
Any "understanding and experience" that says "marijuana is more harmful on the net than alcohol" would appear to be not just imperfect but seriously defective.
For any who think marijuana is harmless
I haven't seen anyone saying that.
and ought to be fully legal, I urge you to consider the consequences of: more doctors, lawyers, airline pilots, and other professionals who are heavy users;
No differentiation there between marijuana and alcohol.
of roads loaded with semis and other vehicles driven by heavy users;
No differentiation there between marijuana and alcohol.
and more schizophrenics wandering around loose and using marijuana, alcohol
No differentiation there between marijuana and alcohol.
"Alcohol use disorder (AUD) is the most common co-occurring disorder in people with schizophrenia." - https://pubs.niaaa.nih.gov/publications/arh26-2/99-102.pdf
As for whether alcohol or marijuana are the worse burden, the common experience and judgment of modern, developed nations makes alcohol mostly legal and marijuana mostly illegal. You may disagree with that consensus but it is not reasonably open to dispute.