Steam has a near monopoly (except for Fortnite, League of Legends, Overwatch, Minecraft, World of Warcraft, you know, by far the most played games) because it provides a service no other competitor comes even close to, without any exclusives AND giving regional pricing that any publisher is free to opt-in or out of. A better gambit? Simple enough, give a better service, better sales, more features, that's how fair competition works.
What you seem to be saying is that "Steam offers excellent quality, and if Epic wishes to break into the market in which Steam has historically controlled >75% the way they should do it is to offer even better quality."
In the first place, I would respond that: that is not how you "break into" a market like this. It is how you sustain and grow once you have achieved a nominal degree of market penetration. If we were to examine the history of the Steam digital retail service, I'm sure we'd find that: early on, most of these features did not exist, not even in embryonic form. They were added as the business grew, they were added as "additional perks" for users and perhaps because there was enough consumer market research evidence to suggest they would make a difference. But the core functionality of the service: advertising, listing and transacting games sales did not depend on such things at the outset.
In the second place, I would say: you need to define all those characteristics you just described (service, sales, features) and enumerate how it is that Epic actually fails to meet acceptable standards much less Steam's standards.
Someone earlier claimed that buying from Epic nets them "no benefit," to which I replied, 'Presumably the primary benefit any consumer can net from buying from Epic is a functioning game.' Beyond that, things like friend networks, individualized Wish Lists, Workshops, etc., etc. are "nice to haves" but not necessarily part of the requisite expectation of a large fraction of would-be purchasers. You, and/or the "Burn the EGS Witch" mob might not like the reality of that, Valve certainly would be inclined to not like the reality of that, but the sales figures for EGS' current offerings should presumably speak for themselves? Assuming we had access to them?
Which is to say: if you are correct, then there is nothing to worry about. Because of its lack of "better service, better sales, more features" EGS will go out of business all by itself, with no extra shilling for Steam by gamers at all.