What's the difference between Korean real estate immigrants and Japanese immigrants?

The gap between South Korea and Japan? The two countries should not be comparable except that they belong to East Asia. South Korea lags behind Japan by several grades (almost every grade).

First of all, economically,

South Korea's GDP is 1.4 trillion US dollars, and Japan's is 5 trillion US dollars.

South Korea's per capita GDP is $27,000, and Japan's is $39,000.

Per capita annual income (this is very different, only from the white-collar workers in the most ordinary companies), the average annual salary in South Korea is 20,000 US dollars, and that in Japan is 60,000 US dollars.

According to various cases around me, the income level of Koreans is about 1/2 or 1/3 of Japanese, and many Koreans' income level is even lower than that of China.