The pandemic forced it on companies. Before that mass work from home is a Decision that needs Metrics to determine if it was right and if it doesn't work or has issues it could be someone's fault with Career Consequences. Without something forcing their hands conservative managers would have continued to take the easier path of having people come in just because the default decision isn't questioned as much.

Working in the office had huge inertia behind it and it does make things simpler for middle management because they can easily just walk around and look over people's shoulders to tell if they're working on browsing HN all day or interrupt for some face to face.