Honestly, they should sue Sony, Microsoft and Nintendo. The fact that we allow such restricted computers that can land you in prison for manipulating them is just absurd.
More realisticly Epic is just choosing their battles where they can see that they can make progress but they can't say that.
They only need one big win. If they manage that, the rest would be much easier. As arguments will have been made and ruled. They can refer to the case against Google as precedent, making the subsequent court cases short, cheaper and/or not be necessary. If Google loses apple, Microsoft, Sony and Nintendo will all examine changing policy or settling any disagreements earlier.
Precisely, it would be a stupid waste of money to launch simultaneous lawsuits against everyone. Get one victory, then use that precedence to get settlements from the rest.
I mean don't get me wrong, it's absurd how locked down their stuff is, but I'm not aware of prison time for opening up consoles yet. You can get sued, like Sony vs Hotz, and get ordered to pay some outrageous restitution, but that road ends in bankruptcy, not prison. Still complete bullshit that they can bankrupt a person, but there's no prison....yet.