A lead actor who could actually... you know... act, would REALLY help this series, due to a lot of the somewhat ridiculous sounding lines requiring an actor that can sell them, instead of making them sound like a bad parody of an action hero.
An awful lot of the writing is pretty bad, but there's also huge inconsistencies with how good the iron fist actually is at fighting or being a hero whenever the plot needs him to become incredibly dumb or inobservant, despite how big of a deal it's already made of him being superhuman in speed and strength and able to notice the slightest things wrong.
Generally the show isn't awful, but it could've been greatly improved by much better writing, and a lead actor who could actually deliver the lines without making me burst out laughing at how hard he's trying to "act" yet still failing to make it convincing.