If you have followed comic book movies for so long then you would know that pulling off consistently good comic book movies is not an easy task. There are multitudes of things that could go wrong. You may not get the right actors, the right directors, the right studio, corporate meddling, poor script, lousy special effects, bad marketing, bad screenplay etc.
For every Dark Knight you would get, you would get stuff like Green Lantern, Johah Hex and The Spirit. Even within franchises, you would get a couple of good ones then suddenly a movie that dips in quality greatly. You would get Blade 1-2, then Blade Trinity. You would get Spider Man 1-2, then Spider Man 3. X Men 1-2, X Men.... First Class/DOFP then Apocalypse.
The franchise consistency in the MCU has been astonishing. More astonishing has been the long term investment. This stuff SHOULDN'T even be possible in the big screen. The scope of stuff like Infinity War and presumably Endgame is beyond any other comic book movie that we have ever seen. It's not just the storyline but the amount of characters they have put into the movie. And EVERY SINGLE actor is near A list celebrity, even side characters like Benicio Del Toro as the collector. Then you got directors and producers who are super passionate about the projects and don't stray from their long term vision. Then you have the perfect storm of being owned by Disney which allows them to have a massive capital on these movies which allows them to make movies with budgets close to $500 million.
It really is the perfect storm for a franchise. They have the talent, the vision, the money, the marketing and the fanbase to make this work. Any one of these things could have caused the whole thing to collapse but damn it they stuck to their guns EVEN when the starting was rocky. Incredible Hulk, Thor and Cap 1 were not excellent movies IMO but you could tell they were building to something larger. And once Avengers came... everything changed. After that the average quality of the MCU movie increased dramatically in my eyes and now we are reaching peaks with IW and Endgame yet again.
It's crazy to think how for we have come. People give MCU movies a shit time and yes they can be a bit formulaic, look a certain way or pander to a broader audience but you cant deny the level of consistency they have achieved in 22 movies. It is a herculean task especially when other franchises go two movies then crater on the third even among super hero movies. So many cinematic universes have started and failed right from the get go. MCU has now overtaken Star Wars WW as THE dominant movie franchise of the world which just speaks volumes by itself. With IW and Endgame it really feels like comic books come to life and the biggest spectacle possible without sacrificing the smaller character moments.
I don't know what else to say other than you have to be a true pessimist to not at least appreciate what the folks over at Marvel have accomplished.