it is highly disorienting and stress-inducing to wake up one day to discover infrastructure you had ties to for over 10 years yanked from underneath you
one can only imagine how much worse it's for freenode staff
(yes, there was an advance notice, a few days, for the freenode to liberachat migration, but it wasn't entirely obvious at first what sort of action and how quickly will be needed, so it didn't help that much)
Since http://libera.chat didn't start with a clone of the freenode data, I didn't really see much advantage of trying to move there.
If I'm going to need to spend weeks nagging people to move, might as well be to Matrix, where our new rooms aren't tied to a specific server.
We started with the IRC channel as the main room and used an inherently bridged Matrix room.
However, 90% of the users in the channel ended up being on Matrix. Main disruption for us is needing to move to standalone Matrix rooms. It's fine since we needed to upgrade room anyway.
It ended up this way because we treated them as equal and always referenced it as a bridged Matrix/IRC channel with people having a choice of platform.
I preferred IRC which is why that was the canonical channel, but our users clearly prefer Matrix and Telegram over it, by far.
If we actually mentioned the Telegram group on our site, I think that would be by far the biggest... but we want people to use the Matrix rooms so we can control it rather than Telegram controlling it. People made the Telegram group on their own, then gave us control of it.