Well in my case, I already had a kitchen table in my bedroom with a gaming PC set up on it. A couple of DSE assessments have since given me a proper, larger desk that can fit the extra kit as well as a total of four monitors to play with. I know it's not my stuff, but there's stopping me from hooking up the screens to my own PC and making personal use of them, as I do. So for me at least it feels nothing like a cost, and more like a free upgrade.
I suppose that statistically they must exist in some numbers, but I would honestly be surprised if the kind of people who would be likely to be working from home in the long term don't mostly, as a group, already have a space in their home devoted to computing activity.