It's more akin to XMPP rather than IRC. From what I've seen, a Matrix server would be more resource-heavy than an XMPP one. Synapse one would probably not run on my weak machine at all, and Dendrite/Conduit are not feature-complete. And the primary reason I still haven't been on Matrix is that I have very limited disk space on my VPS, and Matrix saves media from every chat its servers are on, and I still haven't figured out how to opt out of that.