I agree, and frankly, while I don't wish ill on any particular individual, if the UK loses a little international power and wealth, and that means it's less of an aggressive, malignant stain on the globe... good.
So a wealthy western nation will be a little poorer, so what? If that can equate to say, the lives of a few hundred thousand brown people being spared a violent end, then there's no argument.
In or out of Europe the problems will remain: climate change, neoliberal economics, imperial subservience/connivance, corporate media, etc, etc, etc.
In or out, the people of the UK have to confront these issues.