another note on URIs in RDF and their use in things like linked data and schema.org etc
URIs are often slow moving things. They are often created and managed by humans. The kinds of URI from create edges to store xid while importing data · Issue #1047 · dgraph-io/dgraph · GitHub or in the linked data web or on schema.org aren’t created on the fly by a machine. They are minted by humans, agreed on by consensus and bulk uploaded into a machine. Even when we do mint a URI on the fly, the process to ensure that it’s unique generally happens outside the DB or is based on some data property of the node that’s meant to be unique.
For example a use of RDF might be to have an existing schema with URI that’s bulk uploaded, say about people, and then data about individuals is added/modified on the fly, the people themselves don’t need URIs - they can be blank nodes. Even if for a particular application you want them to be proper URIs, the process that guarantees uniqueness of them has to be external to the triple store’s node ID handling anyway - e.g. a process that mints different URIs for two people with the same name.
So we don’t really miss out on anything in the sense of using RDF if we don’t have XIDs