[Kurtz79]

"In my opinion, Valve also has the same shortcomings as google: practically zero customer support..."

This strikes me as something you can afford because you are in a factual monopoly ("You are not OK with our service ? Find an alternative... whooops :)"), rather than just having a lot of money.

Steam benefits from the fact that even people not completely happy with it (personally I have no complaints, but I use it exclusively as a store/launcher) are already invested in the platform, and do not want the hassle of dealing with two or more similar services, so they are wary of any alternative that might surface (see Windows store or proprietary stores like Origin).