> I'd be interested to know if anyone actually seriously uses something like this. I can't imagine there is much crossover in the irc audience and the people who would want to use a web based client. Even less so when you need to self host it.

It's our default web-based client that we offer for public use over at EsperNet (which as an IRC network has been around since the 90s) - https://webchat.esper.net.

The fact it is modern, easy-to-use and has better security characteristics made it a bit of a no-brainer to switch from Iris.