Even hardware that is made to be run headless ("server-class") is hopelessly broken. They give you a proprietary graphical console that isn't even just a VNC server but has to be accessed with a web browser. And, if the server is more than a few years old, some deprecated, unsupported plugin like Java or .NET will be required. I have an old Dell R710 whose remote console I will never be able to access, because it only works with Java 6 (or so I'm told, I'm certainly never trying that; I wouldn't even know where to begin to try to set that shit up.)