Being in the office for any mandated period of time is pointless. I'd predict that most companies with mandated time in the office will slowly move to a purely flexible model where people come and go as they choose. I'm not against being in the office when there is a specific reason for it (like a team meeting, project, etc) but the 'spontaneous collaboration' and culture reasons are 100% bullshit. Most people are sitting in their cubes in zoom calls anyway. Fire away..m