Will Britain be better off if Celts and Anglo Saxons become the minority?

Wouldn't the UK be better off if the warring Anglo Saxons and Celts gave way to a more pluralistic society of Somalis, Pakistanis, Nigerians, Jamaicans, Russians, Albanians, Kurds, Guyanese, Iraqis, etc.? Many predict that non Whites will become a majority in the UK one day and that it will thrive once it reaches this point. How can we enable this to happen? How can we help to make Islam the dominant religion in England and non Whites the majority?