Matrix literally syncs the entire data/metadata history to all other servers where someone pops in
How else would you expect a decentralized and persistent chat room to work? If that stuff wasn’t synced among the servers that were invited to participate in a room, then it wouldn’t be decentralized; one server going down would kill the room (or at least lose data).
The only way I can think of is not to use servers at all, but go fully peer-to-peer. Matrix has done some proof-of-concept work toward this, but I’m not aware of any service that does it successfully while being practical for most people, yet.
chat is meant to have an ephemeral aspect to it.
There are use cases where that makes sense, but for general use? No thanks. When I lose my account password or my phone breaks, I want to be able to sign in on another device and still have my message history.
It sucks so much RAM, so much storage,
Synapse is indeed a heavy server implementation. Several lighter ones are in development, some of which people are using already.
+1
In case you don’t have an optical drive, new ones cost only slightly more than one CD these days.
Here’s some guidance on which models are especially good at audio ripping:
https://pilabor.com/blog/2022/10/audio-cd-ripping-hardware/
(Note that the best ones cost a bit more and don’t come with a USB enclosure, but could be mounted in one.)