This is all about the real estate.
It’s not about productivity.
Yep. CRE is going to blow up.
^^ That's exactly what this is about. ^^
The productivity of these kinds of jobs can, and are, easily monitored from anywhere there is connectivity whether that's in an office next to a group of cubicles, or from the other side of the planet.
The only time "IT" personnel must be in person, is if they are those that physically install or maintain hardware (servers, routers, etc). The rest can type on a computer/video conference/pick up a phone from anywhere.
The only physical space these companies need are for data centers and the like.
Instead, they have to justify paying for and maintaining (i.e. operating, cleaning costs, etc) their office buildings by mandating people drive/commute in so they can sit in a chair at the office and do the same exact thing otherwise.