NH's miles have a hard expiry of 3 years, and requires you to fly NH for roughly half of the earning, but still has a distance based chart. NH status does get you into United Club's domestically though.

If you're flying NH to TYO/Southeast Asia, UA won't credit for more than 750/1500PQP per segment. UA got hit with a pretty major devaluation in 2023, which means it should be safe for a year or two. For your Econ/Econ+, you'll have Econ+ seating domestically.