Honestly this movie was better than I expected. The CGI is indeed terrible, especially in the opening scenes, but you eventually get used to it and go along for the ride.
Minor spoilers —
It’s pretty funny that Ezra Miller has chemistry with… himself. Michael Keaton was good as well, actually better than most of the recent Batmans.
Overall it’s a fun watch if you can get past the weird looking CGI that feels like you’re watching the 2nd matrix movie.