Disney Star Wars has been terrible for me. The Prequels were bad enough, but at least there was some lightsaber action. Klown Kathy is an abomination. But people keep buying and watching SW, so why do anything different when you are in the black? People are going to buy those atrocious AOTC figures.
Namor is a strange situation. Maybe he will win you over. I wasn't much of an Ant-Man fan, but the first one made me like the character. Downey made Iron Man better for almost everyone. But I only really like about half of the MCU. I rewatched Ragnarok and it worse than my first viewing.
Those are from a deleted scene, but do sum up the movie rather well.
Maybe with casting there is more to it than what we know and certain perfect people just don't want the role or to commit for multiple entries.