Justice League was released in 2017. The movie had a bunch of behind the scenes problems, which is all too common in Hollywood these days, but the biggest hiccup was that family reasons forced Zach Snyder to leave the project and the studio brought Joss Whedon in to pitch hit mid-production. For years, super fans have whispered about a "Snyder cut," the movie's original vision. A bunch of improbable factors conspired to get Zach to finish his version of the story, which released recently.
By contrasting the Whedon version with the Snyder cut, there is much to learn about story. Because the Whedon cut was a chopped up mess, but that's not to say that it was all bad. You can see the priorities of the directors in their movies. Whedon tried to humanise the heroes. Many scenes build connections between the heroes and fill out their characters. Snyder did this too, but he has scenes that are stand-alone pieces that show the heroes being heroic, then two minutes later, they are killing with wanton abandon and don't care about civilian casualties.
Both movies suffer from the same problem. They are set in the Snyderverse. Firstly DC needed to have individual movies for at least all but one of the characters. You can introduce one character in a group film, and personally, it should be the bad guy. Otherwise, you have a sack of malformed characters and a paper-thin bad guy. DC wanted Marvel profits without doing the work that Marvel did. It shows.
Secondly, Snyder’s vision of a "darker" or "more realistic" group of superheroes is fine, but you can't apply it to every superhero. If their morals define a superhero, you can't have a dark version. If a superhero is defined by their pain, then they can have a dark version. Batman’s pain defines him; he has had plenty of movies that explore the dark paths he could have taken. He is a man seeking justice in a system that he understands can never have true justice. If there were true justice, his parents would still be alive; if there were true justice, then the police could overcome injustice, not a dude in a black bat suit who punches people. Batman is himself a contradiction.
In contrast, Superman is defined by his morals. Superman has all the power in the verse. He is untouchable, unstoppable, unkillable. A near-immortal godling. He can use that power any way he wants. Any way. His virtue comes from his personal decision to defend the weak. If he doesn't have superhuman morals, he isn't Superman – just a powerful alien. Great power and average morals is the recipe for a tyrant. There are stories where Superman uses his power to lobotomise "evil doers," they are set in an alternate timeline where the Justice League become the Justice Lords, a tyrannical version of the Justice League.
A Batman who kills is understandable. A Superman who kills is not. Batman's intentions aren't compromised if he kills a bad guy, just his own soul. Superman murdering is just lazy. Not a very superhero thing to do. I've used Batman and Superman as examples, but the same is true for all superheroes. The more powerful they are, the stronger their morals have to be to keep them in check. Batman’s secret kryptonite is more about Batman than it is about Superman.
Getting back to the Snyder cut, the 4-hour movie does a lot to fill out Cyborg and Aquaman, but the Whedon version made Batman a bit more human. Action sequences in the Snyder cut make a tonne more sense. The attack on the Amazons and the final battle is much more linear. I mean, there are limitations. The Amazons are fighting teleporting space-faring aliens with arrows, and they spend a little too much time stopping and talking rather than running for their lives. But the Whedon version was a hopeless jumble, and the Snyder cut showed that the Amazons at least had a plan. Same with the final battle. An ensemble cast in a movie always runs the risk of not getting everyone enough to do, and both films suffer in this regard, but the Snyder cut sets up and pays off story events in a far more comprehensive manner.
If you turn your head off and just watch the Snyder cut as a popcorn movie with lots of explosions and action, it is an enjoyable experience. The Whedon version can't say that; it was a hot mess full of world-breaking plot holes. Not that the Snyder cut is plot hole free, but most of them are character actions, like why doesn't Darkseid mobilise his army? Or how did he forget the location of his only defeat? Or what is the penalty for the Flash's time travel? You can kind of plaster of a lot of those holes with, 'I guess they forgot,' or 'maybe they didn't think about it?' Still, bad things to have in a film, but you can watch it without your head exploding from the stupid.