[spiffytech]

> Yjs has its own “gc” that discards deleted content. Without GC, deleted content remains in the CRDT but is hidden from the user’s perspective.

This alone makes Yjs the clear choice for me. If you're building an app where a user prepares a record and then shares it, senders assume recipients can't view the record's previous revisions from before it was shared (unless your app has an obvious 'history' feature). If a CRDT doesn't do garbage collection, recipients receive past revisions, and could extract those states from the CRDT if they wished.

Without GC, you have to address this by creating a new CRDT with no history each time the recipient list changes, and that breaks offline changes made against the old CRDT.