So why didn't the Enlightenment increase human freedom and end suffering?

If the Enlightenment and the rise of rational humanism was intended to replace the superstitions of religion, and lead to a more civilised society that promised the perfection of man based on the sciences, arts and logical thought, why are we doing such a bad job? Why are wars, starvation, violence, and suffering still occuring if humans are so logical and apparently have all the answers?