The divide between the MCU and the DCEU and their vastly different approaches to superhero films has been a topic of debate for fans of both franchises. The MCU has arguably been more successful overall, both financially as well as quality-wise, and fans of the DCEU often argue that at the very least, DC is trying to differentiate itself from Marvel by making its movies darker and more serious than most MCU entries. And this is true; the distinguishing factor of most DCEU films is that they are dark and gritty, both in tone as well as in color palette.
But is this really the best approach? Sure, DC wants to separate itself from the MCU and be as different as possible, but so far it seems that approach hasn't been working. It's not as if darker superhero movies can't be successful, because films like Logan or Christopher Nolan's Batman trilogy were well-received. The problem with the DCEU is that they're missing one of the most important themes that permeate a lot of Marvel films. That theme is family and the effect that it has on the lives of the characters, whether that family is the one a character was born with or the one they made.
The DCEU does have some widely successful and beloved films, such as Wonder Woman and Shazam!. Taking a closer look at those specific movies reveals a possible reason as to why they were so successful where other DCEU entries failed. Those films, Shazam! in particular, have a focus on family and community. Shazam!'s whole message is about the importance of family, specifically found family, and that's the reason why that film resonated with the audience's emotions. Similarly, one focus of Wonder Woman is Diana's connection to the other women on Themyscira and how much it affects her to see them die in battle or to have to leave them to set out on her own.
Those themes are what bring audiences back, because they get more interested in the characters when they can sense that emotional connection. Rather than just being cold and unfeeling, these characters have emotional connections with the other characters they interact with, and they feel like real people that fans want to get invested in. Building up the relationships between characters in a group is the perfect way to make them feel tangible, as well as to make the team more interesting and complex.
The MCU is pretty good at this. The Avengers are often positioned as a family (especially in Avengers: Endgame), and though they often fight with each other and act a little dysfunctional, it's that familial relationship that makes the conflicts more interesting. It's so much easier to feel invested in a fight between two characters when those characters have a history and clearly have complex feelings about each other (Captain America: Civil War is the prime example of this). Even villains are much more interesting when they have (or used to have) a close relationship with the hero, like Loki or the Winter Soldier.
Of course, the Avengers specifically seem to have more arguing and infighting than the usual family, so perhaps the Guardians of the Galaxy are a better example. They're a group of misfits that come together to form a bond and really become like family to each other, mostly because none of them have a biological family or are estranged from the family they do have. It's a big reason why the group is so interesting, it's not just their individual personalities, but the ways in which they play off of each other and work together that keeps the audience interested. The characters have to care about each other in order for the audience to care about them together.
This is what the DCEU has seemingly failed to do. They haven't spent enough time trying to set up the relationships between their main heroes and establish that they should truly care about each other outside of being colleagues. Again, the DCEU movies that feel the most emotionally successful are those that focus on the connections between people, and those familial bonds. It's strange that they haven't been able to make those themes more widespread across their films. It also seems that when they do try and attempt to insert a story about family, it gets sidelined, or handled improperly.
It wouldn't be that hard to do, either. For instance, Batman stories (at least in the comics) have always had familial themes, specifically in regards to the variety of Robins. Whether it was an actual biological bond or a chosen-family trope (depending on the Robin), those stories explore family in a lot of interesting ways. It's strange that DC has yet to really bring this to the screen, as any of them would be really interesting storylines, and beloved by many fans. Storylines like this, or anything similar, are definitely something DC could and should pull from in the future in order to make their stories resonate with audiences more.
In general, it's strange that the DCEU seems to be unable to capitalize on those familial themes in a lot of their movies, because that's one of the few things that's worked for them in the past, and it's clearly working for Marvel. It's understandable that DC wants to distinguish themselves by using a different tone, but that doesn't mean that they need to sacrifice an emotionally fulfilling story for a dark and gritty color palette. There's a way that they can make themselves both visually and tonally distinct while also giving the audience characters and character relationships that they can actually become invested in, and hopefully they're able to strike that balance soon.