Regardless of whether this is true I do think there is a risk of overdoing it.

My dad firmly believes in the "when people quit work they decline" theory. Which may be fair, but he's not in great health and still charging hard. Definitely think you can overdo that & end up working till you drop

I know I interact with people on the daily with my remote job, but would love to know if that's potentially an issue too. Decent reason to get back in the office. I also miss my daily office bike rides to a certain extent, at least it was healthy for me, now I do exercise by choice and I don't always keep up with it.

Retirement is an artificial modern construct to create jobs. People are supposed to be active until they die. Hobbies are just a replacement activity. I have no intention of retiring (over 60 already). I work in tech and learning new skills and my income feeds and houses my family and pays for my running shoes.

As other commenters have noted folk in some places don't have anything but work. That is a global social issue that needs addressing first.

I don't think this is "work is medicine." It's that too much of normal life depends on having a job, so policy lands on working longer.

Or people who have cognitive issues have trouble staying employed...

There have been studies that show that elderly who interact with children are cognitively healthier compared to their counter parts.

Is there any evidence in this paper or elsewhere that this is causation rather than correlation?

For example, it seems logical to me that people with worse health and failing mental faculties will already be feeling more motivation to retire earlier, as opposed to very healthy people who will keep on working forever. That would be pure correlation

I finally found the reason why my cognitive function feels like that of a 7years old child.

This still smells like the kind of paper that a think tank would fund to justify their billionaire-backed policy that social security should be abandoned and the retirement age moved to 75.