They don't benefit absolutely everyone; that's hyperbolic language. They /could/ benefit everyone in a situation of varying degrees of severity that that person /could/ possibly be in at one time.
Do you think adding qualifiers makes the point any clearer? I think it just makes it harder to read. Accessibility options in video games do nothing for new born babies or people in a vegetative state, but that doesn't really need to be said.
Reason is how you figure out if something meets a criteria. Rhetoric is how you convince people. That's a simple fact of the human mind and not one that can be easily outplayed.