Hulk was really the star of the first Avengers film in a lot of ways, he got many of the most memorable moments. His role in Ragnarok also worked very well. That's almost a buddy film, or parts of it.
Having a big Hulk out in Endgame, after the no show in Infinity War, would have been the obvious thing, but I think that Professor Hulk worked. He even gets to make fun of rage monster Hulk a little.
The rage monster aspect has always been a little limiting and one-note. It was done so well in Avengers, maybe the writers thought that it wouldn't be worth revisiting it.