You say PPEs have bad side effects but as I've mentioned those whom I've asked never explain what they are. Why? And why are they undocumented?
Re sucking dust away, active air pressure masks etc., I agree they're a good idea and ought to mandatory in many environments. I accept sucking dust away as the norm on my table saws and planers etc. but even so I still wear a mask (although not an active pressure one) as the sucking up is not 100% effective. Also, what happens in environments where it is not practical to suck away dust such as a stonemason working up on the side of a building or such? The only solution has to be PPEs.
Its no biggy in an office, and I guess for a ton of people that's the reference "work". On construction sites etc you get a ton of pseudo protection where people pretend to comply to escape the jurists and egghead harassment.
I totally agree that stone lung is horrific, but I also think a ton of laws fail that protection goal miserable on purpose.
So what's the solution? It seems that in some situations there is none. Perhaps in those situations the only move would be to inform people of the risks of not wearing masks and let them decide whether to work there or not.
That said, persons who later develop a dust-borne disease are likely to change their tune when the seriousness of their predicament sinks in and then retrospectively blame their employer for allowing them to work sans masks. Moreover, no insurance company would tolerate such a situation if aware of the fact—hence the laws, even if they're unworkable.