take a look at NexDock - laptop form factor, without the innards. just a keyboard, trackpad, screen, and battery waiting to connect to a phone, server rack, pi, or what have you.
[0] https://uploadvr.com/every-virtuallink-gpu/
[1] https://dancharblog.wordpress.com/2020/07/20/add-usb-c-with-...
Seems like the Pinebook guys could make a decent competitor.