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 ?
To be as generous as possible to the MCU:
Hulk’s power has always come from his pain, and Thanos caught him at a time when he had two adopted families (Asguard and the Avengers).
Also, we’ve seen Hulk lose this matchup in the comics too. His rage is essentially infinite, but so are the resources of the Power, Space, Reality and Soul stones.
Given time for Hulk to get angry enough, Thanos would have lost a fist fight, but Thanos was clever enough not to let that happen.
Edit: And Hulk’s decision not to just close the distance and finish Thanos off is arguably mostly down to his own insecurities (both in the comics and the MCU).