Yea I don't think DC likes the idea of such. Honestly it all is a bit arbitrary and subjective. Especially nowadays.
Marvel only has power grids because of trading cards in the past. Kid's would use power grids to determine which character could beat which I believe....
Don't quote me on that lol.
But Power Grids ultimately are useless and meaningless. Writers ignore it, causing characters feats and information in the comics to completely contradict Power Grids. Like Captain America's old Power Grid only listed him between Olympic Level Athlete - Above Olympic Level Athlete. Yet comics have stated and clearly shown Cap is Superhuman.