See also: Microsoft Continuum, Motorola Atrix (probably the first Android that turned into a laptop)
Yay, and with Emui and DeX growing up, it seems to be next revolution about smartphones replacing your PC's. For instance, the Mirabook from Miraxess : https://miraxess.com/samsung-note-8-laptop/
https://www.samsung.com/us/explore/dex/