I was just thinking the same thing. The M-series is so good, the demand for uber-desktops is smaller than ever. And all professionals I know truly want/need the portability of a laptop.
the iMac returned to its roots as the “family computer” or “grandma email box” kind of machine.
And receptionists! Don't forget receptionists. :)
My preferred setup would be a semi-beefy desktop paired with a highly mobile laptop, which with the current product line would be something like a Studio (or a high end 27”/32” iMac, if such a thing existed) and 13” Air. I ended up with an MBP due to constricted availability of the Studio/Mini, though.