This is going to be way worse than movie streaming, and unlike movies, when one of these companies pulls a game you once loved and it's not available, there will be no pirates to save you, because the software is trapped in the cloud. The future may well be streaming-only.
Mods will be greatly impacted eventually, with only sanctioned mods allowed to run in the cloud. There'll be no deep tweaking, no introspection or learning opportunities. Cloud mod API only.
And it'll go the way of all cloud services: fragmented. You'll have to subscribe to a different one for each game you want to play.
And you won't stop paying. To play a game over the course of 10 years, as many of you have with Diablo or Quake or Minecraft, you'll have to pay your $15/mo to each streaming service, so instead of Diablo being $50, it'll be $1500.
That's before we even start talking about the F2P/IAP/DLC casinos. You used to choose on the character select screen or find items in the game, now new characters are $10 and items are $10 up to $100+, we all know it should be part of the game.
Think, they don't really make arcade games anymore. I guess traditional videogames will die off too. More than one company has quit normal games to run a casino for children.
I guess I'll go pen a dirge for the dying art I have loved.
P.S., thank god for indie developers who make games without input from accountants and psychiatrists who specialize in addiction, they may save us all yet. There's also a glimmer of hope at gog.com where they still sell real games without DRM. I'll keep hoping.