In the 00s I really liked the Marvel movies. Then came Marvel Studios to ruin everything. But even in the beginning, the first couple of films were really good: Iron Man, Captain America and Thor. But once they started to expand the "MCU" I quickly lost interest in the films. I like character driven stories that focus on the person behind the power. Batman is interesting because of Bruce Wayne, Spider-Man is interesting because of Peter Parker etc. When you start doing these big mash-ups and team stories, like Guardians of the Galaxy and Avengers, you lose focus on the individuals and it becomes lots of long, drawn-out & boring action sequences.
But if I remember correctly, Fox held the film rights to the X-Men property. So when Marvel Studios got off the ground, they did everything but X-Men. I don't know if that ever changed.
In any case, I agree. Logan was really good. And it was really good, in my opinion, because it was character-driven and not just 13 hours of drawn out, boring as hell, CGI "porn" action sequences. And I figure it was like that because it wasn't made by Marvel Studio.