Matrix turns every chatroom into a blockchain with a distributed consensus algorithm.

IRC (real IRC) solves this by not solving it, and accepting that message order can differ between servers. If two operators kick each other on two different servers at the same time, usually both get kicked - the command is validated on the origin server and the rest of the network takes it as gospel, even if it doesn't make much sense in their own local state.

Synapse basically brought my vps to its knees with like 5 users. I would not call it light.

Is Matrix really non-bloated? My impression has been that it works more reliably, but isn’t considered lean at all.