This is the crux of the issue. Pretty much every opinion in the ruling has one opinion or another about how the case would've gone differently if the "market" defined by the district was broader. In this case, the market was "mobile gaming transactions".
The district court analyzed anticompetitive effects
in terms of increases in the cost of mobile gaming
transactions—the court’s relevant market. But the court
could have found greater increases in costs if its analysis
concerned Epic’s markets, and this would change a properly
conducted balancing analysis. In essence, any balancing
done out of the context of a relevant market necessarily
involves putting a thumb on the balancing scale.
