If you are the only technical person on your team then it's of course not ideal and would require some further thought into making things redundant. But even that is easy enough to do with IRC (setup two servers, link the irc servers together, single DNS record that points to both servers - job done).

If there are other people on the team that have _some_ technical skills then they can fix it..

IRC lacks quite a few features compared to other solutions, but the reduced complexity does bring very low operational complexity.

IRC will be incredibly hard to use for non-technical people on your team. Mobile clients for IRC look like crap, and have horrible-looking ad bars. No integration with Google Drive, Github, or other things.

It's just not a business-friendly tool.

I'm an engineer and personally I'm fine with IRC, I'm just trying to be realistic here.

Is it really though? If I take a look at a random modern IRC desktop client - how is it more difficult to setup than say your email program? The amount of information needed on setup is about the same: server, username, password (in fact email can get a bit more confusing in big corporate email setups with differing imap and smtp servers, etc.)

Also there are plenty of modern web clients for IRC, such as https://thelounge.chat/ or https://kiwiirc.com/ (which is supposed to work on mobile too).

> your email program

Reality check: Most people don't use email programs anymore.

Also how do you get IRC to sync all conversation data, history, between your several desktops and phones, how do you send files, make calls, and thread conversations?

But clearly no one is saying that email is too hard to use and we should just use $something_else (or are they?).

And you are starting to move goalposts here.. first it was uptime, then it was operations and now it's features...

And what about those web based IRC solutions? They are even easier to use than slack, have combined history, file sharing, etc.

They are moving the goalposts because there are several and ultimately very many reasons why IRC won't work, they just didn't bother to think of all the reasons and list them at once.

Ultimately there is only one reason that matters: The person in charge of deciding what communication channel to use likes Slack/Teams/IRC/whatever.

Add to that the SaaS propaganda that hosting literally anything yourself is just too hard (it really isn't). Or this notion people are just too stupid to deal with anything more than the simplest possible web interface - Really? what do those people even do? Stare at Notepad all day? Of course not. They stare at various complicated software packages ranging from CAD, $spreadsheet abominations, SAP to various Adobe software packages. Sprinkle in a bit of hype for the latest new thing and presto.. </rant>

> Reality check: Most people don't use email programs anymore.

Guess you are not in enterprise.

I'd bet hard money that within epsilon of anyone using a desktop email client in 2020, and thus having one to set up in the first place...is in an organization with access to Microsoft Teams.

Who deals with the downtime if any other on-premises system goes down?

If you are running networks and software on site, and they are business-critical, you have people and a plan for this. Or you don't, and suffer the consequences.