Yeesh. What a suck up, but as always, Bob is completely in the wrong and I wholeheartedly agree with Dr. DeGrasse Tyson here. Despite what Bob wants to believe, the MCU is not art. The only Marvel film that I see as close to a piece of art is The Winter Soldier and the rest are really a collection of popcorn flicks whose main gimmick is their interconnectivity and world building. Much of it is paint by numbers at this point though Bob has the emotional maturity of a grade-schooler and the intelligence of a thirteen-year-old (at best) so he does not mind repetition.
As for superhero films that transcend the genre, I would list Richard Donner's Superman and James Mangold's Logan as two such examples. Your mileage may vary.