Is the world better off when countries band together to in an imperfect, yet democratic framework, or is it better when every country seeks to be independent an

Is the world better off when countries band together to in an imperfect, yet democratic framework, or is it better when every country seeks to be independent and abide mostly by their own short-term interests? If the answer is the second, is this a good time to do it, will it confidently result in better outcomes? I'm an EU citizen in the UK so I'm biased, I don't get a vote in this democratic exercise, despite being half English with grandparents who served in WWII, directly in the defense of Britain.