Under normal circumstances, no one wants to be the first mover on something major like this because it's extremely disruptive to the way most people work without a clear example of the benefits. You're mentioning all of the upsides but there's a lot of execution risk in shifting a large organization to a remote setup. There's also a lot of management layers that are largely redundant with remote working and they've likely fought tooth and nail to prevent it.

Companies have touted open desk workspaces as some grand collaborative masterpiece for years now. It's a very big difference to advocate working from home because you also have to acknowledge that was a total farce.