There are still a lot of specialized editors that are not text-based nor collaborative yet.
In the creative space, we can imagine 3D collaborative editors (think Figma but for 3D). Here is an example built with liveblocks: https://liveblocks.io/examples/3d-shoe-builder
Filling a form can also be a collaborative experience: https://liveblocks.io/examples/collaborative-logo-builder
Building a form can also be a collaborative experience! Think Typeform editor with multi-player features.
All the no-code tools could benefit from multi-players feature. Any "data entry" could be collaborative.
For example, we're working with https://cloverapp.co/ to improve their collaborative features (live cursors on whiteboard and live avatars).
I hope it answers your question