[xyby]

    If you sold every share of every company in the U.S.
    and used the money to buy up all the factories, machines
    and inventory, you’d have some cash left over.

"So by this theory the value of a tech startup is the developer's laptops and the value of a yoga studio is the loaner mats."

Where do you see a "theory" in that statement? I only see a calculation.