[p_l]

Both Prolog and SPARQL/RDF/Semantic Web are used at scale and pretty extensively. Unfortunately often behind closed doors, but there are very performant systems involved.

URIs and RDF in general don't need to use public HTTP links or anything like that, meanwhile the layered systems like OWL and RDFS provide some impressive features for implementing complex systems, especially when you actually want to use a semantic graph instead of loosely-schemed bag of nodes and vertices common in non-RDF graph databases.

[AtlasBarfed]

So sqarql rdf should stick to it's limited application space and let more generally applicable graph technologies go their own way

[p_l]

Except it's actually a superset of those simplistic models.

It's just not getting the "kool" looks and gushing reviews, mostly written by people who totally missed all the previous research. Which is a common problem all around in computing.