What communication problems exactly? What is the difference of working remotely and working in office with your headphones on, only using slack to communicate?

What communication problems exactly? What is the difference of working remotely and working in office with your headphones on, only using slack to communicate? I know several places like that. I’ve worked full time remotely for the last 6 months it’s been absolutely wondrous. I would hate to have to commute and go back to an office.