I switched from IRC to matrix in 2018 specifically because I found mobile difficult.

I used the suggestion in your linked document by running irssi in a tmux session on a VPS I paid for, then using a bridge to an app on my phone. I found the experience to be cumbersome even for someone like myself (and even then irssi required reboots or else it would lose performance over time).

I wanted to use IRC for a family chat, but I couldn’t possibly convince my friends and family to go through the same client setup as I did.

In my opinion there are use cases that either IRC or Matrix would be preferred over the other (not to mention other self hosted communication software).