While it has happened before in comics, we never got to see an outcome where one came on top of the other
Let’s admit this first of all. Marvel has been crushing it with their movies while DC is struggling hard to keep up. While in recent years, DC’s Wonder Woman and Aquaman had pretty interesting stories, Justice League was a big disaster and didn’t even come close to the Avengers.
But let’s set all that aside and see how it would turn out if both teams fought.
A Battle Of Strength Or A Battle Of Intellect?
The Avengers have more tacticians when compared to JL. Iron Man, Captain America, Black Panther, Black Widow, and Mr. Fantastic are some of the few. When it comes to a sudden fight, these guys can clearly have the upper hand.
But JL has the Batman. This is a man, with the right prep time, can come up with strategies to take everyone out, and can do whatever it takes to see his plan through to the end, even if it means sacrificing himself. But it has been shown in the comics that T’Challa, aka, Black Panther has more intellect, but we haven’t seen him doing detective work as much as Batman.
Then there’s Superman, against whom a major part of the Avengers wouldn’t even stand a chance. Thor is the only one, and maybe an overly enraged Hulk (not the MCU’s version) who might be able to do some damage. And even then, Thor would require both Mjölnir and Stormbreaker to make a little headway.
Cyborg is someone who can summon portals from outer space and can hack pretty much anything, so he can go well against Iron Man, that is, if Superman hadn’t already destroyed him first. But if Tony makes a suit of Kryptonite, he might be able to take over the Man of Steel.
We should conclude here, as this can go on and on. Both teams have some insanely powerful members and it would be hard to see who would come out on top.