For sunscreen, they just make a separate less effective version for the US market. The market of people who would say "well, I won't buy sunscreen at all unless it's as good as foreign variants at blocking UV-A rays" is pretty small.

The real harm of the sunscreen thing is that the FDA being weirdly far behind the rest of the OECD at approving new agents means we're stuck with stuff that's a pain to apply and feels gross to wear. This harms health, because people will be less consistent about applying and re-applying when it takes more time than it might, and when the product feels nasty on the skin.

Many grey-market imported sunscreens apply in like 1/4 the time of US ones, feel like nothing at all once rubbed in, don't leave your hands feeling oily and like you need to scrub hard with soap and water right after applying, and have almost no odor. We're like decades behind on that tech, for reasons that I don't understand.