Why Davos sucks
We've already seen Danny beat the crap out of him on at least three occasions.
If Danny had beaten him during the trial to become Iron Fist, and then Davos had beefed himself up afterwards (as in the comic) ... he'd be an intimidating villain.
As is, he's just some guy Danny has defeated once before gaining the Iron Fist (flashback), once while barely able to channel it (Season 1), and again after he'd mastered it (early in Season 2).
All the suspense is gone ... which I guess is why Colleen ended up fighting him in the climax while Danny just faffed around.