The only time I actually need to be in the office is when I need to physically touch something. Realistically, that's a couple of days a month unless I have a big install project. Everything else (vSphere, O365, AD, backups, trouble tickets, environmental controls, security, etc.) I can do remotely.
Companies are rushing to set minimum numbers of days a week to justify their investment in real estate. There is no practical reason for me to be in the office x days a week just to be there.