High debt in the prospect of population ageing

In all countries (United States, euro zone, Japan, China, etc.), the COVID crisis is amplifying the increase in (public and private) debt that has been taking place for 20 years. And in these countries, there is already and will be even more population ageing . However, population ageing makes a high debt load harder to bear. This can be shown in different ways: Ageing reduces potential growth, and therefore eliminates the deleveraging that results from growth; The "young" (who save) must buy the debt from the "old" (who dissave); if the young are few in number, the debt inherited from the past will absorb a significant part of their savings, which will no longer be available to finance new capital; Population ageing leads to increased need for public spending (pensions, healthcare, etc.), which is all the more difficult to meet given the already high public deb t .