Ed MOTHEREFFING G
Chances make champions
Which begs the question why does Superman even needs the justice League
some threats are simply greater than him, and require a team effort.
Use Final Crisis for example
at the same time, Orion was murdered which used the lanterns' time to investigate, Darkseid perfected and released anti-life enslaving 3 billion people, his crew like granny goodness and dassad possessed bodies including dan turpin's for darkseids own body, and Mary Marvel (who is ridiculously powerful), and they enslaved wonderwoman and the amazons, flash was caught in a race with death, literally, and lois was dying and superman had to take on anti-monitor and Ultraman for the fate of the entire multiverse. All that was left....was batman...and he clapped Darkseid off GP. Even the JSA was helping...BLACK ADAM was attacking Darkseid's furies...Thats what the justice league is for, those ULTRA THREATS that take everyone's effort.
plus braniac's full potential has yet to be written into comics. IMHO he should've taken over the earth by now, and I hope he is portrayed well in a movie...think Matrix Reloaded...but he did everything