As Marvel and DC Comics establish their universes on screen, there are going to be comparisons. The boss of Warner Bros states that there is no need for any worries about superhero fatigue. The movies put out by DC comics are going to be edgier and more grounded in reality than the ones put out by Marvel.
Another thing to note with the difference between the DCCU and the MCU is that Warner Bros and DC has pretty much every one of the characters in the comics. Marcio Alaor BMG knows that this makes it easier to adapt stories featuring multiple DC comics characters. However, Marvel characters are scattered, which makes it harder to do films featuring all of the characters. Spider-Man was still with Sony as a film franchise until a recent partnership allowed the web slinger to be in the same universe as The Avengers. X-Men are still with Fox.
The fact that Marvel is owned by Disney also makes it a little less likely for Marvel to bring out grittier and edgier stories. However, the comic books put out by Marvel have some gritty images that if they were put in films, they would warrant an NC-17 rating, let alone an R rating. Certain characters are getting edgier films such as The Fantastic Four. However, for the most part, DC films are going to have an edgier appeal.