This article is like going back to high school health class and defining "well being", but with a personal spin.
"Physical" and "emotional" are connected so closely. If you slip emotionally because of a recent death then physical illness is likely to follow.
Maybe in my teens I thought "social" was hanging out and doing things with people. Some decades years later I see "social" as happily contributing some place in society. "Social" today is more of giving back that hanging out.
Whether it is mental, emotional, physical or social, they all take exercise. Without practice we fall behind. The trouble or maybe blessing is that as we get older, we get slower, we have less energy and our body naturally wants to disengage. This makes daily habits and behaviors like note taking, meeting a friend for chess or just enjoying the moment even more important than ever.
I see it as the same. It is about being part of the community through various forms of interaction, even if they aren't friends.
I wonder if it is natural, or if we tend to just do it more as we have set up our lives to be comfortable. One benefit of getting older is that learning never need stop. We might degrade in some areas, but it is always possible to improve in some too.
You might enjoy this article https://www.nature.com/articles/s41467-025-64173-9