Which is a serious concern of countries with lower birthrates and longer average lifespans?

Countries with lower birthrates and longer average lifespans face the serious concern of an aging population, which can lead to a shrinking workforce and increased pressure on social security and healthcare systems. As the proportion of retirees rises, there may be insufficient younger workers to support economic growth and fund pensions. This demographic shift can also strain public resources and necessitate policy changes to address labor shortages and support older citizens. Additionally, the imbalance can hinder innovation and economic dynamism.