The popular view, probably data supported, is that working in person is vital to collaboration. We need to keep finding and improvising new and better ways to work together virtually, even when we're in the same cities and regions. In addition to the carbon footprint impacts, working virtually makes inclusion more possible because many more people can collaborate and contribute virtually than co-located people can.
We use the trifecta of Trello, Slack and Google Docs. What they have in common are accessibility, easy learning curves, user friendliness, scalability and complementarity. These keep work organized, conversations relevant and products archived. Searches and notifications make staying up to date easy and best of all, everything happens without email and email's way of keeping things and people fragmented, not transparent and burdensome. Email is by far the best way to make collaboration as unpleasant and unproductive as possible.
We continue to see more inventive versions and configurations of tools to make collaboration better.