Yes, large distributed groups where people can drop in/drop out is IRC's niche, and why it will never die. I prefer IRC for large open-source projects to Slack,

Yes, large distributed groups where people can drop in/drop out is IRC's niche, and why it will never die. I prefer IRC for large open-source projects to Slack, but the usability is awful for a company environment. At my school, we use Slack for research groups, study groups, and student project teams, and it's excellent for that.