Lemme ask this:
Who in here is actively reading DC/Marvel comics today?
Like actual issue to issue reading?
Me. And I have for 25+ years
The main difference between the two is how their characters and universes are structured. Marvel builds off the 4 corners of the MU (X-Men, FF, Avengers, Spider-Man) and notice how every character falls into one of those groups through direct or indirect association. DC runs off the Trinity, Superman, Batman and Wonder Woman and everything is build from the heads of those families. Thing with Marvel is because the Universe is built off of team associations, it gives individual characters more room to grow, stand out and actually become a major player, Wolverine, Deadpool, Cable, Luke Cage, Hawkeye and Black Panther, ALL major characters are specific examples of this. DC has traditionally built things around the Trinity, but more specifically Batman and Superman. DC has done a lot, specifically Grant Morrison and Geoff Johns, in defining Flash, GL and the big 7 but DC hasn't made a commitment from leaving the Trinity model behind.
Its like this, you ask 10 people who their favorite 10 characters in Marvel are and you can have wildly different lists with different people, you ask the same people to give a DC character list and they will ALL have Superman and Batman in their top ten lists. Nothing important in DC happens without Batman and Superman's involvement and if you are not a fan of those characters there is no real room for the lesser DC characters to excel and become stars in their own right, word to dikk Grayson.