The Snyder Cut of Justice League made many positive changes to the theatrical version, including one concerning both Batman and the lead villains. As easy as it can be to forget sometimes, Zack Snyder's vision for the DCEU has always been highly divisive, despite the passion displayed by the director's devotees. Many audiences, including a number of DC fans, had a problem with Snyder's Man of Steel and Batman V Superman, finding them too dark and dreary, especially in how they portrayed the normally hopeful Superman character.
In a case of people perhaps needing to be careful what they wished for, though, Joss Whedon's theatrical cut of Justice League arguably swung things way too far in the other direction, replacing darkness and seriousness with the kind of quippy jokes and dialogue found in Whedon's Avengers movies. While that kind of levity may work just fine in the MCU, the mismatch between Snyder's and Whedon's tones was whiplash-inducing. Dialogue went from somber to silly, and it just didn't fit the world Snyder's prior films had established.
This extended to Batman/Bruce Wayne, who was suddenly prone to wry humor, and seemed like he'd suddenly become far more relaxed since Batman V Superman. Batman shouldn't be the comic relief in a DC movie, and unfortunately, every member of the Justice League found themselves put in that same spot. This comedic tone made it very hard to see Steppenwolf, already a rather weak villain as written, as any kind of an actual threat. Thankfully, Snyder fixed that with his cut.
While the Snyder Cut of Justice League is noticeably lighter than the director's prior DCEU films, which he has said was always his intention, the humor is not nearly to the level of the theatrical cut. Batman still gets a few good quips, such as the "I'm rich" response when The Flash asks what his powers are, but his worry about the Earth's possible impending doom and guilt over not being able to save Superman are palpable, and remain so for most of the film. One never gets the sense from this Batman that the stakes are anything but high, and the threat from Steppenwolf and Darkseid is never not taken seriously.
As a byproduct, this makes Steppenwolf and his forces, as well as their boss Darkseid, seem like villains really capable of conquering and possibly destroying the world. This makes a huge difference with Steppenwolf, who no longer feels like a third-rate villain who's not fit to serve as a foe for all of Earth's most powerful heroes at once. Steppenwolf still probably wasn't the greatest choice to fill this particular role, but the Snyder Cut's more serious tone, which radiates from Batman on down, helps improve his Justice League portrayal immensely.
