Warning: contains SPOILERS for Adventures of Superman: Jon Kent #5!Jon Kent's journey into the Injustice universe has explained a Batman plot hole from before the events of the first game. The Earth of Injustice is one of the most brutal Elseworlds ever devised, presenting a world where Joker killed Superman's family, leading him to become a tyrant. In the resultant games and comics, the Batman of the Injustice Earth contacted the Justice League of another world to ask them for help fighting Superman and his Regime, as shown in the game Injustice: Gods Among Us. However, Bruce only made this call after five years of conflict.
https://screenrant.com/injustice-plot-hole-batman-vs-superman/