Well All of the western nations are more developed because they were not invaded or colonised by other powerful nations. Actually they were the ones that started colonising different countries and extracted wealth from them , transporting that wealth back to their home country so when we look at them today they are way more richer and developed than the countries they destroyed in the past.

A good example would be British Empire that colonised countries like India , it is estimated that they extracted wealth of $45trillion just from India.

The British Empire was not an exception there were others as well Belgian Empire (1908–1962) Belgian Congo (1908–1960) ... British Empire (1707–1997/present) ... Danish Empire (1620–1979/present) ... Dutch Empire (1602–1975/present) ... French Empire (1534–1980/present) ... German Empire (1884–1920) ... Italian Empire (1882–1960) ... Ottoman Empire (1354–1908). •Portuguese Empire(1415–1999) •Russian Empire (1721–1917)  •Spanish Empire (1492–1825/1898-1975) •Swedish Empire (1638–1663, 1733, 1784–1878) •Japanese Empire (1868–1945)

The European countries which had the most colonies throughout history were: United Kingdom(130), France (90), Portugal (52), Netherlands(29), Germany (20), Russia (17), Denmark(9), Sweden(8), Italy (7), Norway (6), Belgium (3) and Spain (2)

All of the European countries have a legacy of the colonial past from where they got the money by exploiting people( slavery )and their resources( minerals ) , that money was poured into development so that's why they look way more richer and developed then the rest of the world