Highlights include Sliding Sync (instant login/launch/sync), Native OIDC (industry-standard authentication), Native Group VoIP (end-to-end encrypted large-scale voice & video conferencing) and Faster Joins (lazy-loading room state when your server joins a room).
Since its inception, Matrix has always been “months away” from cracking this very problem, I won’t hold my breath for this one, not after 10 years of kicking the same can down the road.