Appium Doctor was not removed, it was simply moved to appropriate drivers/plugins because it makes more sense in the current architecture. Check, for example, appium-xcuitest-driver/docs/installation/requirements.md at 49c2249e1ae31219be9f0b64bca10c79b5da933e · appium/appium-xcuitest-driver · GitHub or GitHub - appium/appium-uiautomator2-driver: Appium driver for Android UIAutomator2