There afe more than IQ to decide one's country success.
Leadership ; good leaderships lead to good managament, reform policy
Education system ; good education create Productivity workforce, good human resource
Government system ; good admistrative, easy doing business, good business and enterprise policy, good start ups
High inteligent ; skills individual, creatives, invention, good start ups
Culture ; the most important element to liberal, adaption to fast changing environment, good corporate culture, productivty work force.
If a country with high IQ but shitty culture and government, thus produce shtty leaderships, will lead to brain drain, and wasting talent, individual self fishness, corruption...
Vietnam is good example, high IQ but conservative culture especially northern Vietnamese, shitty government where plague corruption, brain drain, government is full of people with relationship and connection, smart and intelligent individuals found no place for use, many idiots can pass school with high degree that are fake, thus produce low productivy work force...etc. the result after nearly 40 years in peace GDP = 2,200 per capital. Look at Japan with good culture, after 40 years they went to second place world economy GDP = 30k or above.