Marvel has the Disney machine behind it, plus their plots are incredibly formulaic and interchangeable. They hire great writers/directors who are talented enough to make sure the movies don’t suck.
DC tried to do all that but without the talent. They hitched their wagon to
Zach Snyder (

) and other directors of questionable talent and it shows. When
Joss Whedon stepped in to finish Justice League, they should have worked a deal for him to take over the entire universe. Or paid Christopher Nolan to do it when they had him in hand.