> Matrix has numerous built-in features (some of which are in a rather half-baked state), often with a tight coupling between the protocol and the expected user

> Matrix has numerous built-in features (some of which are in a rather half-baked state), often with a tight coupling between the protocol and the expected user interface for the features, making Matrix notoriously difficult to implement. citation needed? If anything Matrix doesn’t have enough coupling between the API and the expected UI for features - making UIs trivial to implement (which is why there are so many unfragmented Matrix clients - in fact, I’m not aware of any fragmentation?), but the lack of UI coupling then makes performance harder. So ironically on the Matrix side we’ve been busy adding tighter APIs like Sliding Sync (MSC3575) which make more opinionated choices about the UI in exchange for better-than-telegram perf.