It isn’t harmless. I’m not saying you shouldn’t use it. In all likelihood, it’s less harmful than tobacco or alcohol, but we shouldn’t pretend it’s completely harmless.
Nothing is completely harmless… aspirin and paracetamol is far more dangerous than marijuana.
According to people like you even a water is more dangerous than weed. Weed is dangerous, that’s a fact. Not more than alcohol, but it’s dangerous.
What people always forget is that it’s the dosage that makes the poison. Weed might very well be harmless for recreational use, but recreational use does not mean trying to out smoke Snoop Dog.