They were able to build this device and provide a Android TV certified 4K device that didn't need to have planned obsoleteness.
Feels like a reverse Bell Labs approach. They find their cash cow and only invest in their cash cow rather than research new product areas and fields.
Why would Nvidia give 2 hoots about a living room streaming box now?
I think they had done a minor hardware refresh, at the time it came out it was pretty powerful compared to the underpowered alternatives, plus the promise of pure Android TV on it.
Google “Gsync Pulsar”.
I strongly suspect the reality is that they had to give Nintendo so much money back due to the complete failure of the bootloader security that they still produce the Shield as Jensen still demands they claw their way back to break even.