At the end of the day this is great news for Valve as they really only make their money on people buying PC games (through Steam). You were in a situation where mobile gaming was really only practical on the Switch or phones, both cases that would result in lost revenue for Valve. I can see the Steam Deck as being intended to kind of kickstart mobile gaming for PCs, in which case these other companies joining is a complete victory for Valve as is it provides more opportunities for consumers to spend on Steam.