alt Hacker NewsI think the main problem with IRCv3 is that there are a million optional extensions (see https://ircv3.net/software/clients for a feature support matrix of popular clients)
This can get especially confusing when people on different clients have divergent views of the same conversation. e.g. some can see the emoji reacts, others can't. some can see "replies", others can't.
Emojis and reacts are the only extensions that can cause people to have a meaningfully different view. It's part of why it took so long to ratify replies, and reacts still are not ratified.
We're also discussing ways for servers to provide a fallback to clients which don't support them.