Erin Stellato has started a series on the benefits of Query Store:
The Query Store feature previewed in Azure SQL Database in summer 2015, was made generally available that fall, and was part of the SQL Server 2016 release the following summer. Over the past four years (has it really been that long?!) I have devoted significant time to learning Query Store – not just understanding how it works from the bottom up, but also why it works the way it does. I’ve also spent a lot of time sharing that information and helping customers understand and implement the feature, and then working with them to use the query store data to troubleshoot issues and stabilize performance. During this time I have developed a deep appreciation for the Query Store feature, as its capabilities go far beyond its original marketing. Is it perfect? No. But it’s a feature that Microsoft continues to invest in, and in this series of blog posts my aim is to help you understand why Query Store is a tool you need to leverage in your environment.
Read on for a high-level overview of how Query Store is useful.