Alexandros? Or is it Kinthalis?
Those great games that Sony, Microsoft, and Nintendo make exclusively exist out of a need to differentiate themselves from their competitors, so that you'll buy their hardware over the other's. Otherwise known as this weird thing called "competition". These boxes represent a huge revenue stream not only in terms of the hardware, but also in terms of the walled-off garden ecosystem they draw their customers into. If that disappears, they'll have to recoup that money in another way if you want them to keep making these types of games. Otherwise, one of the possible things that might end up happening is that the individual projects will have to start focusing more on making a profit, which means less risk-taking, which means less games like Dreams and such.
Thank god that console-like devices will always exist though. People will always need a "cheap, small-form factor, easy to handle device" to sell to the mainstream. Whether that be an actual discrete console or a Sony branded smartphone in 2030 or whatever.