Why MCU is great for the film industry!
Simply put, they hire people for big budget films that no other studio would and opt for talent over fame. They could have just hired well known big budget director and well known action stars considering the gamble they were already taking was big enough. But instead we got RDJ as the kick starter hero of the franchise with Iron Man, which turned out to be the best decision commercial and financially. Remember 2008, RDJ was basically a washed up actor.
Behind the scenes, Marvel has hired the likes of the Kenneth Branagh (a hit at Shakespeare in the 80's), Shane Black (One small film under his belt), James Gunn (Two small films under his belt), the Russo Brothers (Small films/TV famous) and of course Joss Whedon (One film/TV famous).
These directors are, in my opinion, fabulously talented at their profession and though I'm not saying without Marvel they still wouldn't be doing great. I'm saying because of Marvel they are now recognised as A-Lister directors who can handle small and big budget films, giving them the opportunity to director just about anything, which given their talent, is super exciting.
Mainly, the MCU is just daring and Hollywood needs more of that. Otherwise we're stuck with Michael Bay blowing stuff up and Bruce Willis pretending like he cares anymore!