Google Stadia is a system, or more like a service, that allows people to stream games to any system to play them. Are you watching a Youtube video of a game and it looks interesting? Just press the play-button next to it and the game is immediately streamed to your system. Be it TV, PC, Phone, Tablet or Toaster, it's all possible.
This has been a plan that Microsoft tried to already push with the Xbox One originally, that you never truly own a game. And with games like Transformers Devastation and Scott Pilgrim already being 'dead' outside of rare physical releases for the former due to licensing issues, this is a scary prospect if this catches on.
On the flip-side, if it works it could be a great streaming service that allows players to access games, new and old, everywhere. The detailing would be really important. No details on what type of payment you'd have to subscribe to, if you pay per game or for the service.
Personally, my biggest fear is that corporations will really get full controle of releases and when we play what. You want to play Sekiro? Tought luck, Sekiro II is out tomorrow so we discontinued Sekiro's original title. You have to play the shitty sequel made by Activision. What are your guys take on this?