Unironically yes because most of these countries‘ population is sick due to low hygiene and water qualify.

Why do they have a young population? What happens to the old people who live in those countries? Why would that not happen in the receiving countries if enough people are imported?

They have a young population because their birth rates are much higher than in (e.g.,) the U.K.

In 1950 the birth rates in Africa were higher than today. Where are those old people?

https://www.macrotrends.net/global-metrics/countries/afr/afr...