We know much less about P vs NP than we do about RH; we can prove weaker versions of RH (e.g. the prime number theorem) and analogues for other number systems (the Weil conjectures). This is unsurprising, since it hasn’t influenced math research for 160 years. Maybe someone will separate P and PSPACE before P and NP, or maybe they’ll fall at once to some brilliant new technique.