In a recent TechDecisions article, Marcus Schmidt, vice president of product management, discusses the benefits of Microsoft's Operator Connect. Here is a section of the article:

Operator Connect 101

While Operator Connect is new, it is more so an evolution of Direction Routing. The tool is a carrier-managed service that makes it even easier to bring their own “carrier” or “operator” to power Teams calling. For reference, Microsoft classifies “operators” as third-party PSTN carriers. Customers can choose from a curated and vetted list of operators to support Teams calling. The flexibility for businesses to choose from approved operators not only makes it easier for them to set up calling, but it also offers greater flexibility and control over their calling capabilities.

Go here to read the full article, Clearing Confusion Around Microsoft’s Operator Connect.