A lot of people work virtually regardless of their location. You can return to the office but it doesn't stop. You still work as if it was remote because there will always be somebody in the meeting that isn't there. They could be at home, in a different building, or a vendor in another country.
Such is the consequence of complex organizations and outsourcing, as well as employees increasing demands to have a say in their schedule.
When you really think about it, collaboration is the problem rather than the solution. The modern distributed nature of work means that you need a huge amount of collaboration to even figure out what to do, when, and to resolve all dependencies.
So it's pretty maddening that managers call for more collaboration. We need less of it. The perfect workflow is where you tell me with clarity what to do, and then let me do it without distractions or changing everything halfway-through.
Modern employees spent half their time in email, chat and meetings. Not producing anything. And that's generous, quite a few have to find actual productive time in the fragmented 10% of their schedule. It's as if we've all become managers.