I forgot about the Chromecast, that's a good point.

Stadia is close to being new, though there have been similar efforts for some time now. However, it is by no means successful so far, most reviews I have seen from the gaming press have seen it as impressive, but ultimately not a great way of playing games, and Microsoft's offering is likely to quickly outshine it by sheer force of games catalog.

Stadia is at best an incremental improvement to PS Now or OnLive afaik. Other companies, notably MSFT and Sony, have been developing this same stuff for years, and Nvidia even has their own version I think.