What market force is going to transform the entire industry from dedicated devices to streaming?
Is it the sorely lacking infrastructure in many places all around the world, not only in the United States? The bedrock of hardcore gamers who care about the quality of the gameplay experience and value-for-money of their game purchases? How about stubbornly traditional Japanese companies, or the indie developers who strive to emulate the past to the point of crowdfunding physical copies of their games, complete with printed manuals? Or is it the competitive gaming communities that dissect games frame by frame, and are the fuel for the growing market for esports?
What about PC games being released directly to end users -- is there any reason to stop doing that? And if there isn't, how could there not remain a market for a device that plays games like a PC, no internet required (once the game is downloaded, when applicable), except it's dedicated to the task so it's simpler to use, less expensive, and more processing-efficient...? Perhaps you could even make a portable version of that, so that you can play games literally anywhere you can keep the device's battery topped up, not only places with internet access to Stadia servers. There's an idea...