Honestly, think Alexa or Google home. While not all blind people are 100% blind, realize that if you want someone who is blind to use your software then turn off your monitor. Is it still usable? If not then there is your problem build from there.
As such the term blind accessible desktop is silly because a desktop is really a UI/UX feature that doesn't fully work when you turn off your monitor. Design from the ground up. Make it an audio focused experience.
This is very true, for the monitor part. But it doesnt have to be voice controlled, as this may be pretty inconvenient and fast enough. I imagine a laptop with the screen removed, or maybe something else just to protect the keyboard. It should still have a braille keyboard and whatnot. Touchpad maybe not.
I feel like desktop controller support would be more accessible than a mouse. A mouse you can put into the void that is your desktop. This is not useful if you don't have vision. You'd not use a desktop UI/UX as we know it for these things. Also, not all blind people know braille. Screen readers are helpful but if you were making a made-for-blind people environment I don't think you could stop at turning up the contrast and putting a screen reader on.