I think the real challenge, at least in the western world, will be getting people to work when retirement at a "normal" age is not on the table. A lot of people work boring jobs with the knowledge that they're done at 60 or 65 and if health permits can have 10-20 years of nice retirement. It's going to be a tough sell for a lot of jobs to convince people to want to just do them until they die. For interesting jobs, I think many do this anyway, but if you're some pointless cog in a bureaucracy, you're probably just counting down days to get your pension. Losing that would make people rethink the whole thing (and hopefully enjoy themselves more)

This attitude of many people makes me sad. Working and thus wasting your whole life in a miserable job and just waiting for retirement. Feels like a recipe for disaster.

Decline in health, energy, mental acuity, motivation. Doesn't happen to all people of course, but does for many.