Er, I agree it's incredibly old, but also has been treated as societal ill and subject to regulation for its entire history.

Should cannabis and other currently illegal substances remain as such?

There's degrees of harmfulness. Weed is on the mild side along with alcohol (possibly even less harmful than alcohol).

They should be extremely tightly regulated, which is all anyone is asking for here as well.

I mean, I don't think we should legalize Fentanyl.

You can regulate the supply of a substance. Gambling is a human behavior. It's a normal human behavior. I don't understand the pearl clutching around gambling honestly.