I think in all actuality, the biggest problem is the ideology that they can be "different". Innovation begins with the notion that nothing is completely "original", and the success of MCU stems from how they built up their universe: Iron Man, as a movie, was widely successful in bringing the character to the big screen. Then, at the very end, they tease the big goal: the Avengers. This simple formula for development hooked viewers into the MCU while they took time to really develop everyone: Captain America, Thor, etc. The main characters they choose for the movies gave even secondary ones the ability to shine after their introduction into the universe through Avengers, so whenever they released a new movie or teased a new character (IE, Black Panther as the latest addition), you were interested and hooked to see what they would create for them. Regardless of their small mistakes, you wanted to see what MCU would put out, whether or not it was good or bad.
While DCU has scrambled as a means to compete, but has not taken the time at all to create their universe outside of Superman or Wonder Woman, which of course, Superman is the most boring character in modern fiction for obvious reasons. The plot they've introduced makes sense and is unique, but the main problem I see is that no one is interested in it because it's not like MCU, that has developed each and every group that appeared in Infinity War. In this quest to be different, yet at the same time, play catch up to a universe that has been extensively developed over the course of 10 years, DCEU has shot themselves in the foot. Their current predicament is the same as if someone who wanted to win a race but is determined to do it without their legs.
They cannot be different and succeed here: no one, especially not with MCU's development looming overhead, is going to care about DC characters and plot when they take absolutely no time to develop them. People do, however, want to see a movie like Iron Man but with characters like Flash, Batman, Aqua Man, etc. It could be a movie about villains too, if they really cared, but it has to copy that setup where MCU leads the way in how they created their universe.
If they are not taking notes and mimicking their development even to a T, they will continue to fail. There is no room for "we can do it differently, and we don't acknowledge that they are the leading group for this type of genre now.", which I believe is their biggest folly. I did believe for a moment they might have changed when they made a movie specifically for Wonder Woman that took time to develop her. But given how they put so much focus on BvS setting up the Justice League, I feel the main reason why they are failing is because no one really feels much pull into seeing what they're doing. IE, I was curious to see Justice League, given that I knew BvS was a giant mess of a movie only because they were doing it to setup JL and I wanted to see what they'd do with the plot. Yet, it's not nearly the same pull I felt for Infinity War, where I didn't really care much about how it'd possibly be a let down in hype: I just wanted to see all of the characters I enjoyed watching on the big screen for the past ten years alone. The key difference being that when my buddies asked me to go see JL and Infinity War, I only went to the theater to see one of them.
And I know for damn sure, no matter how overdone and boring Thanos ended up being (Basically, Ultron reskinned with basic genocide. The Gamora attachment was nice in concept, but I didn't feel much for Thanos because we don't have enough screen time with them to develop the empathy for what comes), no one cared about the little details and execution of plot because they were like me on that front: we just want to see all the characters working together to defeat Thanos. We don't care if he's interesting or even a challenge: everyone we watched from the MCU movies over the years (minus a couple additions like Ant Man), were there and we loved it.
DCU? They can make a better story, a better plot, and make as little inconsistencies all they want (They haven't done better, don't get me wrong here haha). But in the end, they need to take time to develop their universe and not focus so damn much on MCU's success. People will be interested to see their characters shine, but they must first shine on their own before they can try to bring them together. JL proved that: they should have simply made a Batman movie, and then a teaser implying the formation of the Justice League. Just like Iron Man and the Avengers tease.
If they would have done that, that would've been a solid foundation and platform for them to steal interest in MCU and gain a following for their character development process. But obviously, that didn't happen, and now they're paying for it.
