I would say NH having it early lead to Iowa being early but the big push over the last decade where politics = marketability is both a good thing (people paying more attention to politics) and a bad thing as people become saturated with politics.

I think it is more of a small cause at the start of the race to be first but is now a symptom of the hyper political situation we find ourselves in where "above all else we must fight to stay first so we stay relevant" because if we really cared about voting then we would have easy early voting for all. This is a political and economically driven effort not actually something that should matter as much