To draw this conclusion one would have to assume that companies are measuring productivity correctly.
Or that the companies are acting rationally, and we know that's never always true.
So is your argument that bad management is so endemic that every company is making a poor decision about its productivity when it orders workers back to the office? I think some companies want to do soft layoffs. And I think others actually see real benefits of working in-person.
We don't have to take such extreme positions. Doubtless some people are more productive at-home, some people are less productive at-home. And some companies are actually seeing productivity decreases when their teams are remote.
Those people are typically egotistical and irrational. They have big ideas about what makes a good company and they execute them. Sometimes it works out, sometimes it doesn't. They don't require rationale for office work.
They like seeing their engineers in office and so it is done. Why? I dunno. Maybe that's the way it's always done. Maybe that's the way it should be done. We do it right here, not like those other companies.
In actuality, it's because the CEO is a man-child who likes it and then conversation ends there. Does it cost money? Of course. I've seen millions burned in office politics; this shit is nothing.