Not saying that you're wrong, but I'm interested in how you're able to measure "overall team productivity." I've found that to be a near-impossibility at any organization that I've worked at.
For many people it’s really just a gut feeling. That’s the issue with this debate; there isn’t really any data on either side of the aisle. Regardless, team productivity is both more important, and easier to measure than individual productivity; and most proponents of remote work are only focused on the latter.