A wave of immigrants appeared. What is the reason?

Immigration does not mean living overseas. Nowadays, many people immigrate abroad with permanent residence cards. Buying a house and emigrating overseas is a way of investment. Many people apply for immigration to Europe for the convenience of overseas travel. There are still many people who immigrate to big countries like the United States, Canada and Australia for their children's education. Emigration overseas is not to let everyone live overseas, but a way of asset allocation, so that colleagues can enjoy overseas welfare, education and pension.