I am sure that what you are saying is right to an extent. The financial strength of the American scene in the 20s probably had a similar skewing effect.
And does to this day. USA is still boxing Mecca & USA fighters also benefit similar to UK boxers. USA still churns out the most elites but its just less of a % than way back when.
It was a ****ing joke quit being a whiny *****. Short guys with long arms are harder to hit than big guys with long arms DEAL WITH IT.