Obsidian works with Dropbox because it stores unencrypted markdown files that don’t need real-time collaboration — if a conflict happens, you just get duplicate files. Anytype, on the other hand, uses an encrypted graph of operations (a DAG). To stay consistent across devices, this structure needs a sync protocol that understands it. Dropbox only copies files blindly, which can break the graph and cause data loss. That’s why Anytype requires Any-Sync.