Google Stadia

[etoven]

Well, free if you're streaming it to your PC (Google Chrome browser window only of course!) or already own a Chromecast Ultra or whatever it's called, or a high-end Google phone.  Otherwise you need to buy hardware too, to stream to.

It also works on your smartphone or existing PC without the need to buy anything. And most gamers already own a PC.

The only thing that is required is a device that can run Google Chrome.
They even did a demo a while back, they ran the new Doom at Ultimate at a solid 60FPS on a P1 running windows XP.