The identical experience of libera chat makes me realize how useful open protocols are, and how much harder it would be to do something like this with some platform like discord
Not too long ago Slack supported IRC gateways, with limited features of course.
When the IRC gateway stopped working, I found https://github.com/wee-slack/wee-slack worked pretty well. But I switched employers months ago and no longer have to use Slack, which is even better! (So, I don't know how well it works today.)