How do you reconcile this idea with the fact that marijuana is being legalized all over the place?
Marijuana is not a recent invention
1. Marijuana was not invented today.
2. Marijuana is not tobacco.
Tobacco wasn't "invented" any more than was marijuana, both are naturally occurring plants which have been cultivated and used for thousands of years.
Not really. The US has widely legalized gambling of various forms (sports, prediction markets, etc) in recent years. I'd argue that even more so than nicotine there is zero benefit to gambling.