Thank goodness it's Thursday. I'm Diamond Naga Siu, and I miss working in offices: talking with colleagues, eating snacks, and taking in views.

But from a business perspective, these amenities aren't a priority anymore – not even in one of the top buildings in San Francisco.

As far as offices go, One Market Plaza is considered "one of the best, if not the best." Yet its occupancy future is uncertain. Heavyweights like Google and Visa rent there, but their commitment to so much office space is wavering.