Undercuts the arcs of the previous MCU films
In Thor Ragnarok it is shown the Thor doesn't need is hammer to tap into his power, but that his true power comes from within, well it looks like he needs that hammer after all! (And all of most of the Asgardians just die between movies?)
Spiderman says he doesn't need the suit and rejects the offer to be an Avenger in Spiderman:Homecoming, but you can't be a friendly neighborhood Spiderman if there's no neighborhood, so suit it is.
Iron Man gets a surgery to remove his need for an Arc-Reactor in Iron Man 3 so he can go back to trying to live a more regular life, but I guess the chest bling just looked too cool!
Dr. Banner learns to control his rage in his forgotten movie, but it turns out the Hulk persona had a mind of his own. Not enough Zen.