It's all a pretty complex issue.
Like most things, there's loads of fake news by fear mongers. "Every commercial airliner" is obviously not rigged to spray chemicals as some alarmists would have us believe.
That doesn't mean there isn't atmospheric testing at altitude of various compounds, mostly used to alter weather patterns. Or attempt to. Whereas chemtrails may very well be real, "assuming the worst" does us few favors; I know too many people in the aviation industry as well as "airplane buffs" who are so absorbed with aviation as a hobby that they could practically tell you if any given flight deviated two ounces from its stated manifest.
I say "listen and be skeptical."