A modern and properly implemented database engine should be bottlenecked on network saturation for these types of workloads even if backed by disk storage, never mind in-memory. These workloads are trivially distributable, so scale-out is expected unless you are doing something really wrong.

In that sense, similar "look how fast my simple lookups are" benchmarks published by other database vendors are really a function of their hardware budget for the benchmark assuming the implementation is competent. Queries with complex constraints or joins would be a more interesting indication of implementation scalability and performance.