Valve runs a profitable Launcher that allows them to try expanding into ventures like the Steam Deck and pushing Linux gaming adoption even if it ends in failures. That extra cash is what allows for businesses to expand beyond only one field.

Otherwise a company is just stuck being just a reseller, and I think gaming space currently is better for Steam Deck and how it's pushed more people to try Linux. And even before the Steam Deck work on Proton helped. Having profits makes it easier to absorb failures and put resources towards stuff like Linux that is niche and may never gain a significant enough adoption.

Like epic even with fortnite can't financially justify supporting Linux anticheat for fortnite, so I guess that's what happens if a company is not taking in enough profits. And Epic store is only being kept afloat because of fortnite, and is losing money.