Seeing trailers like this and actually watching BvS and JL, etc. I am forced to wonder if all the truly great CG/Special Effects companies are literally all booked up doing Marvel movies and Warner Brothers is forced to hire all the lesser talent that is hungry for work. Because except for Black Panther, which had the worst CGI of any Marvel movie I can remember, everything else has just blown DC out of the water (pun intended). Maybe you could argue that Wonder Woman had good CGI, but then I remember Ares... I mean seriously, if Marvel is pumping out 3 movies a year now, all of which require a ton of CGI, and dozens and dozens of other high-quality movies are also being made that require any level of CGI, there's gotta be a point at which most of the established talent is too busy, right? It sure looks to me like WB has failed in that area pretty hard lately, so it's either something like what I'm saying, or some bean counter convinced them to go cheap. I can't imagine anyone looked at Justice League and thought "Fuck, we nailed that CGI hard!" I'm so glad we saved a buck! Right?!
Caveat, I didn't google anything to support my claim. Perhaps all the same studios worked on both sets of films. But it seems to me that the A Team is clearly assigned to Marvel, and the interns and new hires that still need to get some experience were put on stuff like JL.
EDIT: And I know that all the fuckery with reshoots doesn't help due to time constraints, but Marvel does reshoots and has them look good. Sure, WB reshoots half the fucking movie it seems, but still, whose fault is that?