DC is cursed.
By the time James Gunn launches his DCU, either the Superhero fatigue will completely set in (if not already evident by the reception to the recent MCU flicks) leaving them nothing to milk from or World War 3 itself will begin.
Ironically, had they followed the original plan, we'd have gotten 2 more Justice League movies with Darkseid's invasion at the center of it along with a set of duologies starring each Superhero, including Ben Affleck's Batman - all closely connected to each other - and WB right now would be rebooting their DC Universe through Flashpoint either way(without all the unnecessary drama).
Instead, they wasted all their valuable time by making low budget crap that no one asked for. Now, they want to make MCU 2.0 when people are already getting tired of Marvel's formula.