Man what in the actual fukk are you talking about? You need to do some research.
The Spider-Man trilogy had nothing to do with the MCU. Neither did those X-Men movies. Spider-Man was Sony and X-Men was Fox. Marvel was struggling financially and sold off the cinematic rights to damn near all it's popular characters which is why, when they finally decided to make movies, they had to go with The Avengers. The first movie they made was "Ironman" in 2008.
If "Ironman" flops then Marvel stops making movies. Nothing after that, including "Infinity War", happens. Marvel will get most of their cinematic rights back in 2019 because Disney is buying Fox, which owns the X-Men, FF4, Galactus, Dr. Doom, Deadpool, mutants in general (which is why The Scarlet Witch and Quicksilver were never referred to as mutants in "Age Of Ultron")....pretty much all their characters except the ones owned by Sony. Which is a moot point because Marvel obviously has a deal with them to use Spider-Man.
And no, "Thor" and "Captain America" didn't do better than "Ironman". Hell, they wasn't even on equal footing box office-wise until "Civil War".
So....yeah. Like dude said RDJ is the reason for everything that comes after.
Fred.