I am the only remote person at my work. Sometimes I feel there's too much going on on Slack at the same time, and I haven't had any issues getting the information I need in a long time. There's always exceptions. Even though we've hit a few bumps in the road before we got to where we are now, I think it can work even for a 'traditional' company like ours (as long as you obsess about procedures and keeping things documented and in writing, which we've always done).