/System/Library/CoreServices/SetupAssistantPlugins/LaunchServices.flplugin/Contents/MacOS/LaunchServices
/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/LaunchServices
macOS Launch Services is an API that enables a running app to open other apps or their document files, similar to the Finder or the Dock.
The binary is a part of CoreServices public framework.