Comment by Arathorn
I'm sorry you had a crap time, and agreed that in the past things were not great. But in defence of the Matrix team, we fixed almost all known encryption in ~Sept 2024, and the new generation of clients fixes the slow sync issues.
In terms of message retention: https://element-hq.github.io/synapse/latest/message_retentio... is how you should have/could have cleaned up those rooms. (It's not exposed in Element's UI yet as we've been prioritising more fundamental stuff).
Hi Arathorn, I recognize your name as the core developer lead. :) Alas, when I was trying to cull my old messages I tried that (and a lot of other API type hacks I found floating around) and none of them, at that time, worked.
In short: the complete lack of user-facing easy to use controls for data retention and culling in the Matrix (Element) clients is a deal killer for me. That painful experience taught me a lesson - now when I test something new, one of the first things I look for is "how do I extract from this thing?". I never want to go through my Matrix extraction pain again, so a personal life lesson was learned.