Earth is wrecked. Just absolutely trashed, like the post-nuclear scenes from Terminator 2. We got a glimpse of this ruined-future world in Batman v Superman: Dawn of Justice and we see Batman in his full length khaki trench, making his way towards what probably used to be Metropolis.
Joker continues:"I often wonder, in how many different timelines do you destroy the world, because frankly, you don't have the cojones to die yourself?" Now, this may or may not be setting up the multiple timelines plot that is reportedly at the centre of The Flash's standalone movie, which is said to feature both Affleck and Michael Keaton in the Bruce Wayne role. The movie is still in pre-production, but is currently scheduled for release in November 2022.