I find the idea that humans have already found their ideal system of government suspicious. Democracy is, at best, low-hanging fruit. I do think it is a step up from previous systems, but it is unlikely that it is the best system that will ever exist. Changes in styles of governance tend to be slow, so whatever "better than democracy" systems are out there, I don't expect to see any pop up anytime soon. Whatever it is, it will probably be weird.