I think that's NJPW's fault. Yeah he's in a cool faction but since he came back from excursion they have not given him anything noteworthy.
He has the talent, one year in the G1 O-Khan wrestled a different style every match and most of his matches were a top 2 or 3 on the card.
NJPW went all in with Tsuji giving him a World title match basically in his first match back from excursion. O-Khan did get a singles Match with Okada early but didn't win. He could have benefitted from beating Okada in a nontitle singles match in his first big match back from excursion.