Earlier quoted context omitted.
Out of the zillions and zillions of weed smokers over the past 100 years, there has never once been a reported case of someone dying due to carcinogenic responses to the smoke. Granted, there has never been a formal study, but there have been adjacent studies and by all intents and purposes it appears to be safe. Google around: https://www.google.com/search?q=marijuana+lung+cancer
Today we have have vastly stronger, concentrated wax/oil that can be up to 99+% THC enabling much faster and bigger consumption. Weed consumption and delivery will continue to be refined, a fatal dose is "impossible" only until it is not.
With THC, you'll be more likely to reach a threshold of total discomfort and/or unconsciousness before you reach the fatal dose.
It's self correcting like Mushrooms. You can take an insane amount, but there is a good chance you'll be transported to the center of hell for several hours and never ever want to go back.