What’s so difficult to understand? The state or lobbying groups want to raise the retirement age which then correlates with studies on how raising the retirement age has “good effects”.[1] The goal isn’t to find out what is good for senior people. It’s to find reasons to enact the policy that they wanted.

Surprisingly, men ages 51–64 (this was specifically about men) “need” their jobs for their own health.

We could imagine studies done in more patriarchal cultures: unmarried women over the age of 40 suffer from psychological and physical health problems more than married women over the age of 40. We’ll just leave out the parts about how unmarried women are penalized socially, constantly. Policy recommendation: we should get women married, it’s just good for them.

[1] This was the hypothetical laid out in the original comment.