Capitalism is incompatible with reproduction.
It annoys the hell out of me when many assume women/FAB liberation is the sole reason for low birth rates. Yes it has played a part but revoking the rights of women/FAB is not going to solve the problem.
People (who are open to) are willing to having children if there is supportive economic and social conditions. This means both parents shouldn't have to be forced to work fulltime, younger generations should be able to afford homeownership rather than compete with wealthy pensioners or rich foreigners for assets. And there should be guarantees that parents can take time off work to care for their children without fear of losing their jobs.
UK and USA have higher birthrate because of young immigrant families; as well as the USA's depraved abortion ban but that will have severe consequences.
So even if countries like Norway with supportive family-friendly policies face declining populations. This shouldn't be viewed negatively, a declining population can be managed through immigration strategically via replacing the working force with migrants, but we know how unpopular that policy is, and neoliberalist countries take it too far prioritising immgrants for cheap labour rather than replacing sectors that have shortages i.e state care and health.
However, hypercapitalist countries like the USA, UK, South Korea, and Japan - immigration only serves as a temporary fix, a feeble bandaid, it won't solve the demographic crisis. These countries face deeper issues that deter young people (who are open to) from having children, including high living costs, misogynistic policies and attitudes, and asset hoarding by wealthy older generations.
Having children is both bloody expensive and time consuming. People (who are open to) will not risk having children, especially in countries that fail to provide adequate incentives or address other pressing matters such as housing shortages, restricting reproductive rights, inequitable distribution of wealth, climate change, and widespread violence (mass shootings, wars). Moreover, we should definitely respect the rights of individuals who choose not to have children and accept soft declines in populations will be inevitable.