Some Windows 10 app shortcuts remain available on the start menu even if you have uninstalled the app associate to it. If it bothers you, you can manually remove the shortcuts.
If you are installing a new app on Windows 10, the installer of the app will commonly add a shortcut to start menu to make it easy for you to launch the app. Normally, the shortcut will disappear as you remove the app. However, as mentioned earlier, not all apps delete their shortcut from the start menu once you uninstall them.
To manually remove a shortcut from start menu, you can go to the Start Menu folder on the Windows 10 system to find the app you want remove the shortcut of and delete it. To do so, right-click on the icon of the app on the start menu and select More -> Open file location.
You will be taken to the folder that hosts the shortcut of the app you want to remove its shortcut. Simply delete the shortcut file and you should not see it on the start menu anymore.
Please note that the step above applies only for desktop apps (apps you installed via binary files). If you want to remove the shortcuts of the universal apps (apps you installed via Microsoft Store), you need to completely remove the concerned apps.