You are thinking server. Linux is also about the desktop. And you will shutdown your laptop more often to preserve battery, particularly on laptops where unfortunately, suspend to ram is not working.
Same for a console like SteamOS.
What is promissing is that any game that would be running under SteamOS could also run under Ubuntu, a general purpose distribution for which you can install many desktop applications. You cannot do that on Android or iOS.
Unfortunatly, us Linux users are stuck with flash 220.127.116.112 as Adobe has abandonned the plateform, unless you use Chrome. We are not moving fast enough away from flash...