From one analysis I read, the Socialism in Britain after WWII deprived it of its rightful place in the world political order. It was still significant, but by nationalizing steel and other industries, much of the economic power that should have belonged to post war Britain was lost.
A point. The socialist Coal Industrial in Wales at Aberfan placed their coal spolies on a mountain over a spring. One day it collapsed over the Aberfan village killing 144 people including a school full of children. Because it was nationalized nobody was held to account and nobody was charged with the deaths of theses children.