Within Element, new features are developed in cross-functional teams and released in tandem; e.g. Spaces was released on web and mobile at the same time.
On performance - there are definitely some performance issues with matrix clients in general, particularly larger rooms and accounts which are in many rooms. This is an active focus of development, e.g. see work on sync v3, a more efficient matrix sync protocol https://github.com/matrix-org/sync-v3
hrm, maybe this was true a few years ago?
Element currently develops two web clients. Element Web: https://matrix.org/docs/projects/client/element and Hydrogen: https://matrix.org/docs/projects/client/hydrogen
Element also sponsors development of at least one other community web client that I know of.
Meanwhile, you can find Element's Android client here: https://matrix.org/docs/projects/client/element-android
And the iOS client here: https://matrix.org/docs/projects/client/element-ios
Within Element, new features are developed in cross-functional teams and released in tandem; e.g. Spaces was released on web and mobile at the same time.
On performance - there are definitely some performance issues with matrix clients in general, particularly larger rooms and accounts which are in many rooms. This is an active focus of development, e.g. see work on sync v3, a more efficient matrix sync protocol https://github.com/matrix-org/sync-v3
Disclaimer: I am an Element employee