I know three expats who worked into their 70s. Two were on their second marriages and trying to save for retirement after their first wives had finished "asset stripping"
The third was ready to retire at 60 but lost his life savings in an "investment" scam and had to start all over again.
Thats why I suggested that your examples may have worked on because they couldn't afford to retire. In rare cases where people work on because they enjoy it the reason for their good health becomes obvious. Doing something you enjoy too much to give up promotes well-being. Many expats work on until they drop because its the only way to remain on location. The residency visa expires with the work permit but they love the place where they are working too much to leave. Sadly, not all expats have a huge pile of tax free cash stashed away in off-shore accounts.
**********************************
Through difficulties to the cinema