In a previous article, I had written about distributed tracing and how it can be implemented easily on the Elastic stack. I have used many observability platforms, including NewRelic, Splunk, and DataDog. All of them are very powerful platforms and have everything you would need for implementing full-stack observability for your applications.
Elastic is generally used for fast and powerful content search and log aggregation and analysis, but it has gained popularity recently for full-stack observability as well. It has pretty much every feature you would want in an observability platform, including support for applications written on a modern tech stack, support for tracing/logging/metrics, powerful out-of-the-box agents, visualizations and dashboards, alerting, AI-based anomaly detection, and so on.