My understanding is thanos didn’t use any power of infinity stones in the infinity war fight and hulk wasn’t previously injured very badly . He almost seemed to easy to be knocked down why ? Shouldn’t he have grown stronger because he is angry because everyone is dying and he is getying beat up ?
Hulk has rarely been treated consistently from one project to the next.
In his Edward Norton movie they went to great pains to show its the heart rate that makes him change, then threw that out the window when he was recast.
We just don’t know the rules on this incarnation of the Hulk. We don’t know that he will always get stronger.
And I’d have loved to see two entities fly out of Banner-hulk’s body when The Ancient One stops him. But we can’t have a good Hulk story until the rules are defined and true character growth can happen stemming from that.