The population of the UK + Germany + France is 212 million people and the british colonies combined (USA, Canada, Australia, NZ) is 400 million. Only a few percent of europeans immigrated to the new world, so why do the colonies 2x outpopulate their home countries population combined?
Your comparison is a little strange. The only one of your comparative colonies with a higher population than the UK (67m) is the US(329m) therefore adding them together makes your comment seem like all of them outnumber the uk so adding them makes no sense to me, like why not add India whose population is over a billion. For the US however not only was it not just Europeans that settled, the US is also much bigger than the UK (which is smaller than Texas)with access to more native resources