You can run multiple instances of Simulator to speed up tests by running them in parallel, or test apps that coordinate tasks such as syncing to iCloud across multiple devices. Easily launch Simulator from the command-line, even when driving multiple instances — perfect for automated testing. And Xcode Server is simpler to set up on all of your Macs, as it's now built into Xcode and no longer requires a separate macOS Server app. It’s never been easier to continuously build and test your apps.
People who had worked on automating testing in iOS environments know what this means. It's such a huge work done.
for example,
The macOS Server app is now part of Xcode. // This is great work, explained in a simple sentence. Removes lots of complexity of setting up these things and understanding those complexities.