they can, but they don't. Part of their argument seems to be that mobile is now a general purpose computer like Windows so it should open up. The big 3 consoles don't try to pretend that you can make host much more than games and movies on their devices, and the consoles operate on much thinner margins than the mobile market.
You can say it's cynically about money and that Google/Apple are the biggest targets. You can optimistically say it's that Epic knows consoles do more to deserve their 30% and aren't just gatekeepers (there is a LOT more support for AAA devs from the big 3 consoles than anything Google/Apple offers. Including direct help in porting if you strike deals).
We're seeing more handheld PC's, but the days of the Vita or 3DS as dedicated handheld consoles seem to be past us. There's a non-zero chance PC far in the future does the same to regular consoles too.
It's one thing to say "this is how the law should be, so that Apple should have to open their platform"; it's quite another to say "as the law is right now, Apple should have to open their platform."
If the courts get it wrong then you have to go to Congress, sure. But then you're in the same place -- convince Congress that it's bad.
Either way we're having a debate about whether it should be allowed. And the answer is no -- this business model is anti-competitive, for any business, and if existing interpretations of the anti-trust laws don't currently prohibit it, they should.
And still Apple is the one being sued.
The way that anti-trust law works is that if you have more market power, like Apple clearly does, then you are even more subject to the law and required to do certain things.
But also, if you disagree, then feel free to sue those other groups.
They all have closed application ecosystems and don’t allow third party stores.