I watched this movie from a different perspective than most comic book movies, because of all the info before it was released.
This was a movie about "what if the worst person in the world, just an absolute insufferable cunt with no redeeming qualities, had superspeed & time travel powers?"
Viewed from this perspective, it was not awful. Watch a superpowered insufferable cunt destroy the DC universe so his mom can live a few years longer, oh wait never mind, destroy the DC universe so his daddy can get out of jail.
It was like a supervillain movie where the villain wins, with no comeback from the good guys in part 2. Dark. And meta, because it really does seem to be the end of the DC cinematic universe too.