Didn't Matrix (or whoever owns Matrix) buy Gitter? That was my understanding...
Ah, the joys of open source: where "nobody has implemented 'mark all as read' on a space yet" is extrapolated to "half-baked and just a bunch of hacks".
Custom emojis & sticker packs exist as per MSC1951 (thanks for linking it), and implemented in various clients. The fact the data is stored in a room shouldn't exactly be a surprise, given 'rooms' (i.e. persistent decentralised pubsub topics) are the main primitive for storing data in Matrix, much as everything is a file in unix.
Sorry you feel Matrix feels half-baked; meanwhile we're busy doing a major iteration as per https://fosdem.org/2023/schedule/event/matrix20 and https://element.io/blog/element-x-experience-the-future-of-e.... Right now the target is more WhatsApp/Signal/iMessage style messaging than Discord/Slack/Teams, but we'll (re)address the latter eventually.
- Can't "mark all as read" on a space. probably because rooms within a space are only tangentially related,
- No custom emojis or sticker packs (their proposal for this is to create rooms to house custom emojis/sticker packs[0])
Not a great bet to go to keybase with the Zoom acquisition https://news.ycombinator.com/item?id=28814210
0: https://github.com/matrix-org/matrix-spec-proposals/pull/195...