San Francisco Office Buildings Discounted 75%?

Sobering articles recently that describe the huge discounting of older San Francisco office buildings. One example is 350 California St., 22 stories, 300,000 square feet and built in the 1970’s. In 2020 the value was estimated at $250 million, but now may sell for $60 million!  Another example is 550 California, once priced at $160 million but now may sell for $53 million.