Comment by marijn

I'll be the first to admit that ProseMirror's change representation is a bit messy, but I don't think that's the root of the issue here. The problem is about generalized tree-structured document representation (as opposed to the flat-string model of Quill). I believe such a representation has value, and is the appropriate choice for a system like ProseMirror or its successor. Joining and splitting blocks is not a weird quirk of ProseMirror—it is a basic, essential editing operation. But there doesn't appear to be a known appropriate way to map that structure to a CRDT in a way that can properly express such splitting and joining. And that's fundamentally limiting the approach taken in y-prosemirror.