NH is relevant because the media says it is relevant. They lavish attention on NH and make all the locals feel special, and tell the rest of us that the vote there is a “bellwether” that all the smart people pay attention to.
Oh, yeah...they’re ‘special’, all right.
NH is relevant because it gives everyone in the nation a chance to see the candidates doing person to person campaigning. We try to weed out the worst candidates, like Mike Pence.