3bet pot CO vs UTG.
CO bets 1/3 range on the flop, check some monsters like KK on the turn.
Villain checks river on the Ace and Hero doesn't go allin with his hand despite having a massive nut advantage and an almost nut hand. Even more, he never goes allin, most of his range just bets 2/3.
Does this happen because hero lacks air to bet bigger?
Thanks!