You say that like it's an easy thing to do.

For a relatively novel data model with potentially unusual performance characteristics, the chance of finding a properly done, fair, and generally understandable benchmark is virtually impossible.

I think the model from the user point of view has been seen many times over the years.

See eg https://en.wikipedia.org/wiki/List_of_SPARQL_implementations

https://en.wikipedia.org/wiki/Datalog#Systems_implementing_D...

Also the various RDF things from the days of semantic web enthusiasm.

For active competitors, maybe the various GraphQL things and