Remember how originally, Green Lantern was supposed to be the launch pad for the DCCU? Remember how they talked about Wonder Woman and Flash being next? Then Green Lantern came out and after that everything else was effectively nuked until Man of steel and Arrow? That is what would happen if the MCU were to fail.
Imagine the next 4 films of MCU were box office misses? Not saying they will be, but imagine that? Ant-man ended up like daredevil 2003, Cap Civil War didn't make budget back, Doctor Strange was critically panned and GotG 2 was a hollow copy of the first. You'd expect marvel to either make drastic changes, if not outright cancel things to either save money or curate what may not be up to quality in. Now, that is projects put to the side or not made at all.
Imagine all of Marvel was under MCU and that happened, imagine if there was a Wolverine MCU movie in talks and a Fantastic Four films being cast... Then they were gone, cancelled out right because a few bumps in MCU. That is the reality of the situation and I don't want that to happen where we are twiddling our thumbs waiting for this or that character just to have them pulled away.
I felt DC learned this lesson by green lighting both Arrow and Man of Steel. As both stand as their own universe from the other while building a distinctive universe for that medium. Also, it allows exploration on things you'd hesitate to say exist in the same universe or don't want to narratively have to explain.
Dat Tone Tho
Something that is constant across MCU is one unified tone across all of the them, with very few exceptions (Daredevil being a noticable one). I'd never expect something like what Punisher Warzone wanted to be (Hardcore decapitations, bloody and gore while trying to be serious) in MCU, just like I'd never expect something like Iron man's kind of over the top humor in an X-men film. So having that variety is better than having one series of one tone with a few moments of different tones.
Amount of Content
MCU/Disney owned Marvel is two or three films a year. While yes it's film production is great, it is still only 2 or 3 films from a universe with literally 1000s of stories and characters. Disney not having spider-man or X-men or FF allows more films to come out overall and even allows spin off stories to happen with more supporting characters. ALSO,it means not having to worry about it steps on toes of any story of these other characters like MCU has to in some situations.
Lack of character rights is right mother of invention
MCU has gone 10 years getting around lack of X-men & Fantastic four, and in both cases. They have found satisfying loop holes around that and plays in established lore (like the background of the twins merging parts of Hydra from Cap's story and Tony Stark 's past as a weapons dealer). It makes people think outside the box when writing these and creates moments that aren't just a new version of a 20 years old comic.
I don't expect most people to agree fully, but even if you don't there's got to be one part of this you possibly do. Comments? Questions?