Especially now, I’d assume more people are doing work at home _and_ at the office. Sure, you could get two desktops and probably for cheaper, but then you have the cost of time wasted switching contexts and messing up file sync, etc.

I personally work from home but go to a coffee shop as my “office” for a bit every day. Mobility is crucial to my, and many others’, workflows.

Even when mobility just means from the office to the kitchen to the couch, that's a pretty big benefit.

Cheap compared to what you get in similarly spec-ed non-Apple hardware. This will blow the pants off a similarly priced ThinkPad.

I work 90% at home... but my job requires a computer 100% of the time.

If you make 120k, travel once per month, and you waste ~3 hours of productivity each time you can't take your desktop with you... you would have made up for the difference between a $2k desktop and $4k laptop just in wasted labor.

when you work on computers your whole life its nice to be able to get outside every once in a while

If they can (really) deliver Desktop performance, then they are (really) cheap. There is nothing on the market that can deliver such performance that isn't desktop. But the jury is still early on that one, I'd wait for the reviews.