basically how i see it is it only makes better sense from a consumer standpoint if the decreased developer cost is ALSO decreasing the upfront user cost to buying the game, as the worst policy that Valve has on steam is that the games base price has to be the same on all storefronts.
however in reality, most developers do not pass some of that savings to consumers and just take the cut for themselves. So devs are basically playing againt future benefits on growing a larger consumer base on a different platform for more upfront profit.
basically most of the investment money that epic throws is thrown at development and developers, and basically outside of free games, none of it is thrown back into making the platform better for consumers. Developers can complain however much they want that steam has a “consumer monopoly” (while ignoring the fact that other companies like Riot, and mobile game companies with PC clients like Mihoyo does fine without steam). this will continue to happen until epic reinvests some of that money into their client, or devs actually use the benefits of taking a lower cut and biting the bullet and regularly passing some of it off to consumers.
regardless of the situation, developers are stopping developers ultimately if they want to break the “consumer monopoly”