"I cannot possibly comprehend the mindset behind someone who would choose to use Slack for these purposes when IRC has existed since the 80s and accomplishes th

"I cannot possibly comprehend the mindset behind someone who would choose to use Slack for these purposes when IRC has existed since the 80s and accomplishes the same task much better." Define "better". For many people, Slack is easier to use, has a better UI, and is better supported on mobile devices.