Yeah when you dig you'll often find out "decrease in productivity" is in the noise of the data. CEOs and managers enjoy control and surveying their minor kingdoms. I think it's more about ego than efficiency. I know that I am dramatically more productive at home. I hate the distractions at work. The random drop bys, the "do you have a second", the "15 minute (oops 1 hour)" meetings that could be done over slack or email. It's ridiculous. I know it really depends on your work and personality but by and large managerials are type A with egos and they are starting to feel less important so everybody needs to get back to the office stat.