My experience is that companies almost never own their own buildings - at most they may have a long term lease, and even then long term is maybe 5 years.
Commercial real estate is a highly complex beast. Some companies build offices and sell them to an affiliated REIT while guaranteeing occupancy rates, banks build their office towers and go through great length to turn them into cash assets. It is very different from state to state due to taxes and regulations.
My experience is certainly limited. Seems to me, for a bank to enter into that kind of arrangement aligns much more with the core skill set vs tech companies in the typical HN community. But even then I could see the FANG companies with a lot of guaranteed cashflow owning, but at some way down the scale to smaller companies, I would think it strongly becomes to something to avoid for tech companies.