It identifies a "health risk", describes the mechanism in terms that sound very convincing, assigns numbers to its cause and effects, provides a table grading health risks of various products, all without linking to a single scientific study demonstrating that the effect is anything other than nocebo. The closest they come is a image of a table that refers to a few institutions that apparently did a study related to PWM (leaving it an exercise to the reader to find the studies they're supposedly referencing) and a link to a Wikipedia page which links to a Scientific American article which says:
> In 1989, my colleagues and I compared fluorescent lighting that flickered 100 times a second with lights that appeared the same but didn’t flicker. We found that office workers were half as likely on average to experience headaches under the non-flickering lights. No similar study has yet been performed for LED lights. But because LED flickering is even more pronounced, with the light dimming by 100% rather than the roughly 35% of fluorescent lamps, there’s a chance that LEDs could be even more likely to cause headaches.
I'm willing to entertain the idea that LED flicker is actually problematic, but I wish essays like this would be honest about the degree of confidence we have given the current state of the evidence. This piece instead takes it as a given that there's a problem, to the point where they confidently label devices on a scale of Low to Extremely High health risks.