You can pair a bluetooth keyboard and mouse, it was shown in the keynote.
The issue is that all those desks are different, and I am not carrying the same setup everywhere. I am not going to bring my monitors and cables and the rest on a flight to visit parents. Or if I am working from a hotel. And I am not carrying my entire setup every time i switch between working in the office or at home.
But just a headset + kbm? No problem, especially since consistency of the setup being the same is guaranteed, and the setup time is zero.
But that's probably not the exact point you were making and yeah, I'm in the minority.
Just don't dismiss my corner case, por favor.
If anything, this headset could use cameras to superimpose your fingers on keyboard if you can't memory type.