I fail to understand the 3 days a week concept. If a company needs in-office interaction, why not make it 5 or 10 working days a month in office, and then let t

I fail to understand the 3 days a week concept. If a company needs in-office interaction, why not make it 5 or 10 working days a month in office, and then let the team decide when they want to be there? Some teams might prefer being in office 5 days straight and then 25 days remote in their hometowns.