As long as the shared universe is built on character-driven stories, it works. Up to End Game, the MCU was built very much on character, particularly the twinned stories of Iron Man and Captain American, who acted as foils for each other so that End Game was not just an epic battle but a satisfying conclusion to those and other character arcs.
Since then...there's what? The Spiderman films are great because they are kind of their own thing and very much built around character development. Shang Chi worked as well because, again, very much built around character and kind of its own thing. Maybe Black Widow. Everything else, and everything on D+, seems primarily concerned with moving forward the franchise and the setting, so that nothing seems to go anywhere and the stories are hard to emotionally engage with. They are mostly empty spectacle...and the spectacle is less and less fresh.
Up until End Game, MCU films were almost always narratively tight - they were interconnected but films felt more or less complete in themselves. That is seldom the case since then. Like, if you are planning to go see The Marvels you are expected to have seen the first film, plus End Game, plus Wandavision, plus Ms. Marvel, plus Secret Wars...it's a lot of prep.