The existing tools for monitoring Kubernetes offer very limited capabilities compared to Dripstat.
You can deploy Dripstat Kubernetes alongside these tools and see a comparison for yourself.
Prometheus + Grafana
The Prometheus + Grafana stack, while open source, is very inefficient.
It requires you to learn a query language and know the details of Kubernetes internals to gather its metrics and create custom dashboards. There are a few community made Kubernetes dashboards for Grafana, but they can often be buggy and maintained. Even then, they only offer a fraction of the features and visibility that Dripstat Kubernetes offers.
There is also the fact that with Prometheus + Grafana being open source, you need to have knowledge of, maintain and upgrade all its components. Dripstat is SAAS, so you can just deploy our agents. We even have 24x7 support to help you in case of any issues.
NewRelic or DataDog
Both these tools, just have single 'Kubernetes' dashboard. Kubernetes monitoring is more of a tickbox feature than a full fledged solution.
Datadog does have 'container monitoring' but its not designed with Kubernetes in mind. For example, its 'CPU usage' of containers is presented as percentage of a node, which is fairly usesless from a Kubernetes perspective where you want to see it in terms of Millicores. Not to mention, Datadog only shows data on a single container level, and cannot aggregate/filter it in Kubernetes terms, eg showing cumulative resource usage for a particular namespace.