It was, someone already pointed you to ircV3 which attempted to bring a lot of modern features to irc. But besides the specification process being slow you also had to content with all the different clients and networks. Most of which at that point in time already had stagnated in development.

If it supported things like picture messages, then it wouldn't really be IRC any more. I suppose you could create a new protocol that's most similar to IRC, but when creating new protocols, people typically want to make other improvements at the same time, such as the ability for a user to stay in a group while offline.

In my opinion, most of the differences between IRC and Slack/Matrix/Discord/etc stem from trying to keep users in a group chat while they're not actually online, since this requires servers to store message history, and then you're legally required to have a way to moderate the message history, and you might as well send back-history to clients who just joined, and so on. Additionally, since each message is stored authoritatively on the server, it can be updated with things like text edits and emoji reactions.

Some of the differences, like being able to send pictures, do not stem from that.

I read and responded to a similar comment recently here on HN about email security. The gist of the question is "why don't we create something like email but secure?" and the gist of my reply is "if we created a whole new system, we'd add all the things we can now have that we couldn't have when email was invented, like instant notifications, and then it would be a reinvention of a newer protocol (I didn't name Matrix, Fediverse or XMPP), nothing like email.". https://news.ycombinator.com/item?id=42633785

Because there is nothing wrong with good old IRC. It was developed to a point and left alone. Trying to improve it could actually lead to overengeeniring and spoiling the protocol. If IRC is not what you want, look for alternatives. There are plenty of those.

Moxie Marlinspoke thought hard about that, here’s his conclusion: https://signal.org/blog/the-ecosystem-is-moving/

> I've always wondered, why was IRC not developed further?

Personally, part of the charm of the IRC protocol is the simplicity. You can implement a client effortlessly in most languages in just an hour or two.

The instant messengers did that.

Then slack did the modern IRC client.