Make an iPhone and corresponding docking station, where the docking station is a MacBook shell + screen + touchpad + keyboard + battery that you slot the iPhone into in order to use the iPhone as a laptop. The slot you push the iPhone into would be reminiscent of the PCMCIA slots of old, but having the dimensions of the iPhone and connecting via ThunderBolt 5. When slotted into the shell, no part of the iPhone will extend outside of the shell. To eject, you push it in slightly and it pops out same way you push on a microSD card to eject it from many devices.
Maybe they could call it an iPhone Duo. Oh wait…
If you have a USB dock that your keyboard/mouse/display is plugged in to, you should be able to stick it in your Pixel phone's USB jack and get a desktop experience. Some of my team would actually test keyboard support that way, by plugging a keyboard into a tablet.
I would describe the experience as... passable. Historically it was quite glitchy but recent OS updates have improved it. The biggest issues resolve around apps which do not scale their UIs correctly.
Google probably wants it so they can extend their app store empire to desktop apps and games.