@olmitch@pasture@Christmas_Man@ademan as a single user you're fine. you can keep overhead low, no issues. when you run a public service matrix server and you have users who expect to be able to join any room it gets bad. matrix stores room states in the database and normally this is fine but if you join a room like #matrixHQ or any of the like 60k+ user russian rooms your server begins storing states for every user in that room. tracking every device they've used. any time they changed their avatar or name, joins, parts everything.
normally thats not an issue but they don't provide a way to easily conduct maintenance to prune these from the database. in fact, if you prune them you will break your server. you have to compact room states in order for the room to still function on your homeserver.
right now on disk our database is over 600GB. when I compress states (which takes over a day and a half to complete) it saves maybe 150-200GB. in a month it will be back over 600GB. it's a constant monthly struggle I'd just like to avoid dealing with entirely.
mostly ephemeral irc with a custom client that supports those (and much more) features than matrix with the expectation you could run it on a dinky single thread 512MB VPS instead of requiring a fucking 32 core EPYC server and NVMe PCI gen 4 in a raid10 just to handle a couple dozen rooms is a much better position I'd prefer to be in