Maybe he meant in the sense that they filtered out the shovelware and asset flips from Epic Games Store (at least until recently) so to make the store look good. That way they’re providing hosting only for the games that actually will be downloaded a decent amount of times, avoiding wasting storage on bad/forgotten games.
But hosting is basically a rounding error in the equation of selling games on an online store. The actually significant cost is going to be in developing and maintaining the software powering the online store, and that cost is fixed. This in turn means that having less games in the store is an obvious disadvantage, not an advantage.
I quite doubt that, infrastructure to provide Terabytes of bandwidth per second isn’t cheap, and employing people who are on watch 24/7 and maintain it all, aren’t cheap either.
…I don’t mean to be rude, but you shouldn’t speak to things you do not understand or know about. Cloud hosting costs for a large e-commerce site are rather large, definitely variable and not cheap.
Cost of developing software is also not fixed over any meaningful period.