There are plenty of graph databases, and RDF is expressed in triple stores. OWL is just for validation.

I’ve used AWS Neptune as a pretty reasonable managed sparql query engine but for most my needs actually just local jsonld mastered in git is plenty for almost APO knowledge graphs I have.

I’ve found LLMs are exceptionally proficient at authoring sparql, and quite clever. This isn’t surprising given there’s plenty of sparql in the corpus, and it’s semantics aren’t HUGELY different than SQL. Likewise they do fine writing datalog etc.