You’re right, in practice tho itd work like dex having your own customized environment with all your files and software, except itd use whatever hardware its plugged into, imo if it had become common phones would be the hardware its usually using and encased in, plugging in to a computer would give you dex mode, hence working like dex (but not hardware wise when in desktop mode)

Kinda like external gpus when they were popular with slim and thin laptops hardwarewise going from laptop to desktop in the same environmennt.

Would be cool for android to have a desktop mode that uses the hardware its plugged into, let you boot from your phone like a live usb (I think thats what live usbs are)