Why is Britain a Most Economically Developed Country?

because the GDP for the country is high, the GDP stands for Gross Domestic Product, this is just a fancy way of saying how much money the country produces. GDP percapita is another way of saying the GDP but for one person. The higher the GDP the wealthier the country so England obviously has a high GDP.

But don't be fooled knowing the GDP does not tell you how developed the country is England is a developed country because of things like adult literacy, life expantacy at birth, the amount of people working etc.

Hope it helped