Mental illness including schizophrenia is indeed related to cannabis use. And smoking can cause emphysema. To say otherwise is lying. Look it up in places like this, written by people who (unlike you) actually know what they're talking about
https://www.cdc.gov/marijuana/health-effects/mental-health.html
Oh, and to say that we're all going to develop emphysema because of the burning season is equally daft: lung damage is cumulative, and nobody forces people like us to live in Thailand.
Oh, and you'll call it a freedom of choice thing, which it is until its effects enter the family sphere, destroying lives, particularly when smoked by the young. Then you'll go bleating for help.