the big thing in terms of support is developer testability. just like with the deck, it's basically a given that it will see significantly better support from third parties than any normal pc. it's the same reason that "you can build a pc with the same performance as an xbox for cheaper" was always irrelevant: the marketing push behind the platform is what drives devs there.

also, considering valve isn't selling this at a loss, the prebuilt only managing to undercut it by €40 is quite telling.