the fewer chilfren people have the better. The wrldpopulation is far too high for the planet to support them with out planetary damage, why else do we have global warming?
Thankfully two thirds of all countries in the world are at population replacement level or below. That includes the UK. Our population growth is solely caused by immigration. A statement of fact, not of personal bias. The same applies to all the advanced countries in the world. Italy, Japan and Korea are among the countries with the lowest birth rates. I hope that within the next century world population will halve.
Obviously this will cause structural problems, but when does the world not face major structural problems somewhere or another. Wars kill off people,predominantly young people, so do natural disasters and pandemics. WW1, as well as killing millions of mainly young men, overlapped with the pandemic of Spanish flu. Most victims of Spanish flu were between 20 - 40 in age, where with COVID it was mainly the elderly.