Who is the court, or any of us, to say what should be the charge for selling a game on a marketplace? That's like someone telling you what your profit margin should be for a product that everyone wants. Why should it be tied to your costs?
I mean, in many cases it is, due to customer demand reasons, but there are tons of things that you pay for that have prices nothing close to what it costs to provide.
That's why I think it will fail in court at least (maybe not the SEC, or Congress). The argument that 30% is unfair goes nowhere in court -- so what should it be? Courts are not the forum for that question.
Anyway, I finish with snark: if Epic invoked its same logic on itself, clearly it should reduce its profit / subscription charges to a "reasonable" level. Epic is the only one I'm able to buy Epic games from -- clearly they're a monopoly and need to have their market-abusive behavior and extortionate pricing regulated? Right?
I find irony in many people who get probably so knee-jerk opposed to Google/Apple and "on Epic's side" will find themselves justifying why they should be free to set their own prices when they launch their next product.