Is the influx of immigrants from various countries a good thing or a bad thing for the host country?

Every coin has two sides. A large number of immigrants are definitely unfavorable to various social welfare and facilities in the host country; However, if high-quality immigrants, such as those who immigrate through investment, can often bring rich capital to the host country, and if high-end technical talents immigrate, it will be of great benefit to the development of technological research in the host country.