The only time I would personally choose IRC is if my use case targeted retro systems with limited CPU/ram/network connectivity, or I am integrating with somethi

The only time I would personally choose IRC is if my use case targeted retro systems with limited CPU/ram/network connectivity, or I am integrating with something that uses IRC for some reason (like the back end for Twitch chat). If I actually cared about decentralization above other concerns, my next choice would be Matrix. For literally all other use cases, I would be on Discord or Slack. Users are likely already familiar with it, likely already use one or both, and I'll have to answer a lot fewer technical questions.