The Datadog statsd agent is not really a normal statsd client: it implements a large subset of the original (etsy) features, but also some Datadog-specific features (about histograms). It is used to send metrics to Datadog APM, and its big advantage is the developer experience, which is familiar and easy to use, just like any statsd client, making it trivial to replace an existing statsd metrics client in any application with the Datadog version to publish metrics to Datadog.