DC has a big problem with its film making. It doesn’t matter whether we’re talking about the DCEU or old DC, there’s one thing that will always make it hard to make good, believable films with memorable or even likable characters. The villains will be even more of a problem. The problem is power.
Let’s use Superman as a prime example. He’s pretty much invincible unless they introduce some kryptonite. He’s strong, has frost breath, laser eyes, flight, speed and pretty much nothing can stop him. The solution to Superman is one of two things: Lex Luthor (in the Reeve’s films) who tries to make a plan that can succeed if only he can delay Superman, or a character of similar or higher power (Zod or Doomsday) would have to fight the Man of Steel.
Look at Wonder Woman, Green Lantern, Shazam or anyone else that’s a god, alien or supreme being. How can movies stay believable with lore that makes everyone indestructible powerhouses?
Compare that to the MCU which started with experimented human, rich robot man and weakened god. The MCU started with fairly human heroes, ones that could only be attacked with technology similar to what they had. It stays believable and leaves them something to upgrade to as they slowly build toward magic stones and a giant purple alien.
The DCEU starts with gods and aliens. The Justice League film has a guy that can take on the League as they first create it but then Superman slaps him around like a tennis ball and uses minimal looking effort to beat him. They now have to top this villain for the next film to give Superman a challenge, or they need to write Superman out of it again.
Now look at Batman, it’s relatively easy to make a Batman story because he’s human which means his power will always be limited. Sure, Batman’s rich so he can have all the best technology, even fictional technology if he wants it but it will always be beatable or breakable. A man dressed as a clown, a penguin or a giant wrestler are easy to put in a film, even a giant weird zombie man or crocodile man are humanoid and have a power level weak enough for the right tech to compete with.
DC have an issue with power and believability which means for their movies they’ll have to get things just right to avoid disappointing the fans.