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).
The counter points on the site you posted are either completely expected or even desired properties of distributed systems (like not being able to force a delete or room closure on another server), or just problems with specific implementation details or insufficient clarity in the specs (like interop hickups or handling of media files). As far as I can tell nothing on the list is an “unfixable” protocol bug or core design flaw.