As far as I know, there is no similar phenomenon in any other country.
The problem is:
China's elderly people are relatively poor in cultural life, so they tend to pile up when there are activities they are interested in.
Most of China's elderly people live more lonely lives, more empty nesters, so they will focus on doing activities.
Now people are more concerned about health, and the lack of suitable sports activities and facilities, while the square dance place is relatively easy to find, but also do not need a lot of props, so sought after by people.
Those are the ones that come to mind for now.