It’s actually not unusual for some Windows 10 systems to still have Internet Explorer 11 present, even after official support ended. Microsoft has disabled it for most use cases, but unless you’ve removed it via “Turn Windows features on or off,” the executable may still be there and can launch. Removing it through Windows Features will clean it out and won’t break anything for most users, but a handful of legacy enterprise apps or sites might still require it (though modern IE Mode in Edge is the recommended replacement).
As for safety, it’s strongly advised not to use IE for regular browsing-security updates have stopped and vulnerabilities won’t be patched. If you need it for a workplace app, consider switching to Edge’s IE Mode instead, which is supported for these legacy needs. Most users can safely remove IE11 without any issues.