Top management considers all workers to be equally capable and replaceable. Management at the lower levels requires people to manage at their location (direct superior always at the same location). With full remote work there is no reason to employ people in locations with non-minimal wages. If there is no employees in a location there is no manager managing them either.
It is not managers belief to be able to more easily watch what their employees are doing in a real office. It is just a matter of securing their own job.