InfluxDB 3.0 measures up against Microsoft Azure Data Explorer (ADX) in terms of its flexibility and ease of use for managing time series data, offering both cloud and on-prem solutions, as well as a range of features such as API access, schema-on-write, and real-time processing capabilities. ADX, on the other hand, is a relational database that supports time series workloads but lacks the flexibility of InfluxDB, being only available as a managed cloud solution on Azure and not supporting on-prem or edge deployment. Both databases offer features like OLAP workloads, batch processing, and data visualization capabilities, but InfluxDB's open-source Apache Arrow ecosystem and interoperability with other ecosystems give it an advantage in terms of extensibility and scalability.