Well okay, let's be honest and real here: EGS doesn't need to "survive", it can keep going indefinitely as long as it's at least in the neighborhood of breaking even. Epic Games could care less about being a couple million down (with their billion(s) in Fortnite income) if that makes some kind of headway in their anti-Steam crusade. It'll only really "fail" if it closes entirely, and with how little that store must cost to maintain (with the virtually nonexistent dedicated backend piggybacking off the existing Fortnite infrastructure) it won't cause a significant enough monetary loss even if it sells absolutely nothing.
What you said can prove to be completely right or completely wrong depending on a variety of factors. I think it can be reasonably assumed that the EGS is now operating at a loss under the logic of loss leading. Between the sizeable moneyhats and paying for sales out of Epic's pocket, I don't think there's currently a realistic scenario in which the EGS is at a break-even point. So what would have to happen to reach that point? The EGS would have to attract a large audience and achieve significant sales numbers without moneyhats and subsidized sales. Can it? I don't think so. There are literally zero reasons to shop from the EGS if games are available elsewhere.
Let's move on to the publisher/developer factor. I think it's also safe to assume that game sales on EGS aren't setting the world on fire. This likely means that developers will be asking for bigger moneyhats for their future games. Will Epic manage to drive enough sales through the EGS to convince developers to sell exclusively through the store without moneyhats? I really doubt that.
Then there's the Fortnite factor. As long as Fortnite brings in the big bucks, Epic can keep the store running in the red and continue moneyhatting to their heart's content without much issue. Will that always be the case? Will Fortnite prove to be the evergreen title that consistently brings in lots of cash or will that change sometime?
Lastly, there's the factor of Epic's expectations for the store. Did Epic make a plan for when they expect to reach profitability? How will they react if their expectations are not met? Will they double down on moneyhats and other anti-consumer bullshit? Will they change their mind and try to be more consumer friendly?
Lots of unknowns. We'll see what happens.
