I’m speaking specifically about the Irishman, a movie I love btw. But do I think it is more artistically “valid” than infinity war? No.
It is less creatively “risky” than not doing another gangster film, thats simply a fact. And that’s okay. On some level, it is a “lets get the gang back together for one more ride” movie. On some level, all the players involved have certainly earned the right to do that. But it is odd to criticize studios for essentially taking the exact same approach to film making, especially for movies with massive commercial success - even if you argue that the quality of the art produced isn’t the same.
Pacino’s role is a good example. He practically admitted that he was too old for the role off Jimmy Hoffa after filming, in multiple different interviews. So why was he chosen? You said it yourself - people want to see one of the most beloved Italian American gangster actors get directed by one one most beloved Italian American gangster directors. And you are a fanboy over it. And that is okay. I “forgive” you or whatever. I am too.
It goes to show that formula film making can produce great films, and that the MCU movies that are bad (for many are fine films) aren’t bad because they are based on comic books, or because there is multiple of them. Comic books that were extremely artistic and considered important works of 20th century science fiction in their own right (talking about Jack Kirby specifically). I would argue that eventually the MCU did become a very cynical excercise that is determined more by studio number crunching. That happens for all sorts of reasons in Hollywood.