If iFixit starts selling steamdeck motherboards, can you buy just a motherboard and make a console-only version? Same motherboard, just no screen, battery, buttons.
And a SSD I guess.
Alternative question: Do you want steam to offer a console only version? Same motherboard, just no screen or battery.
The Steam Deck works so well because the screen is only 720p, and even then people have complained about low framerates on some games. Scaling it up to 4k for a modern TV would drop the performance even more.
It looks like a great handheld, but I think trying to use it as a console wouldn't work.
You can do that, but be aware, upscaling with FSR takes a performance hit. It's not a big one but can make the difference between stable and unstable 30FPS.
I use Deck mainly docked in 1080p. The only issues I have are with very recent games. After some questions and learning, I've come to expect not to use it for current big-name games. To that end, well optimized modern games like Powerwash Simulator run fabulous. Most of my Steam library plays very well and is perfectly enjoyable!