Little known facts about the DCEU and Zack Snyder's films:
Marvel only greenlit Captain America: Civil War movie after Batman v Superman was announced. The directors admitted it (
link). Civil War carried the theme of the rupture of the Avengers up through the snap in Infinity War and the redemption in Endgame.
What less people know is that the original ending to the 2017 Justice League had Darkseid invade Earth with the evil resurrected Superman as his general. The Justice League would lose to the big bald alien and the next film would take place after a time skip and involve time travel by The Flash to save the day. Sound familiar?
I'm not saying that Kevin Feige and dem heard about all of this and stole the storylines from DC, maybe DC stole from Marvel who knows.... But the fact remains that Marvel would not have gone forward with this plan if DC hadn't announced their 'superhero deconstruction' plan first (again, they admitted it), so I would guess that the company and director-producer, Zack Snyder, with more confidence in the plan was the one who originated the plan.
So basically DC was responsible for creating the MCU's most celebrated story arc.