Where?
It's not.
His feats do live up to his claims. What damage has he taken when he had the Almighty active? None. Ichigo only hit his Getsuga when Yhwach turned it off. The first "death" was because of Aizen, and his final death was due to Jugram, Uryu, Aizen, and the arrow.
Bankai is a powerup, not really an ability that affects him. The bankai still got destroyed regardless. When he "makes" whatever he sees his ally, he's saying it can't be used to hurt or defeat him. Ichigo's bankai worked because he didn't actually "see" it cuz Aizen KS.
He also broke all bankai in all futures, effecting every single timeline. Only reason Ichigo got it back is because Tsukishima made a past where it wasn't broken. Even Orihime couldn't reject the events until Tsukishima came in because of Yhwach's Almighty.
Yhwach changes the timeline to where he can hit her, and she can't change it at all. Or the Miracle comes in and wins it for him.