There is nothing like having elderly parents to learn about how the eldercare systems work.
For most people, seeing parents age gives an opportunity to think about what the last phase of one's own life will be like, but for expatriates whose parents live in the country of birth, knowing how that country's services work is not much help if one expects to grow old abroad.
This article mentions a trove of American resources worth investigating. One of the linked brochures has a checklist that one doesn't have to be old to benefit from.
Regardless of social status, loneliness and feeling that one doesn't belong are among the main reasons immigrants leave a country to which they have located because of good job opportunities.
Loneliness is even more widespread among older people who no longer have "a daily dose of colleagues", and many immigrants jump to the conclusion that it is their foreignness, not age, that leads to the feeling of not belonging. So instead of doing something about it where they are, they consider relocating "home" - even if this will take them away from their children.
I have in previous posts reinforced how important it is to find oneself a "pack" for one's emotional health and happiness. Reading the article on aging makes the point even more poignant, particularly for expats who are not on a few years assignment but have become permanent residents or citizens of their new country and expect to live out their lives there.