As a software developer do you genuinely believe that it is harder for indie game developers to build online infrastructure and pay for its hosting costs rather than build some LAN feature into the game, or to package local server binaries into the game as it was done just a few decades ago?
Most indie games I've play don't even run their own online infrastructure because of costs. Why bother, when you can just use a storefront's matchmaking for free? And storefronts provide it as a means of soft lock-in. For example one of my favorites, Deep Rock Galatic, doesn't have crossplay between the Steam PC version and the Xbox PC store version of the game.
And there's already software to emulate Steam's matchmaking because it's so common.
