My opinions on Iron Man 3, Age of Ultron. Endgame's humor take of Thor, Thor Ragnarok's humor are not unpopular. If I remember correctly Whedon himself confessed some major problems with Ultron and for Iron Man 3 there was an apology issued from Marvel itself about how the humor used for the Mandarin.
https://comicbook.com/marvel/news/ho...ing-to-shane-/
I was been artistically objective about the humour criticism about the joke of the Avengers in the trailer and why it did not land well, that has nothing to do with general audiences.
I think the joke could have been cut out or be put before the end credit trailer, maybe it would have merged well or flowed better since I even missed it on my first rewatch or maybe what they could have done is not put the interference line, only to end with making Avengers joke when Avengers is the perfect definition of interfering, this is why Avengers are the biggest crossover team.
If they have never interfered or don't really like interfering, why do they now want to lead the Avengers (even if it was a joke)? It just does not flow well, Marvel has had some good trailers, but this is not their best both in dialogues or visuals. The Shang CHI trailer was better or at least appeared stronger.