This right here is the entire reason. They like to say things about collaboration and innovation, but commercial real estate is really the reason (and tax breaks).
I wish companies would just be honest and tell people, "look we know you don't like it but it's better for our business because we need those tax breaks and real estate price support".
Edit: Instead of replying to everyone, I'll add it here: the tax breaks are butts in seats tax breaks. They have already committed to long term leases or own the buildings, so they can't get out of it by "just closing the office". They can't close the office. So they need those butts in seats tax breaks and if they own the buildings, they need the prices to stay high.