Google and carriers deployed changes to RCS which have been breaking it for many users on the stock OS including with certain carriers and in whole countries. The changes appear to have specifically impacted GrapheneOS users too. It’s not related to our September 8th update. We’re working on it.
You can find many recent threads about people having issues with RCS in Google Messages while using a stock OS with Google Mobile Services. There are articles about how some carriers and countries no longer have it. It still works for most people but the changes definitely regressed compatibility.
GrapheneOS users were impacted by these recent changes much more than other users. We don’t know why yet but we’re working on determining that and restoring compatibility with Google Messages for people who use it. We’ll try to get compatibility with the new way it functions implemented very soon.
Matrix for sure still has issue, but its getting better constantly imo. I havent used discord for 7 years so i dont know what i might be missing, but i dont feel like i am missing anything. I got instant messaging, voice/video channels, screen sharing, etc. I dont care about stupid bots and stickers and such so maybe that would be an issue for people.