Both claims can be true (all salaries lower, PhDs paid poorly). I don't have a PhD, but from what I've heard in the US, PhDs are paid pretty poorly there too,

Both claims can be true (all salaries lower, PhDs paid poorly). I don't have a PhD, but from what I've heard in the US, PhDs are paid pretty poorly there too, compared to their level of education and the level of work they do compared to, for instance, a software engineer with a Bachelor's.