Basically, it has both issues. Your rationalization is valid, and its one side of what's going on. Society de-socializes, the clubs and activities still exist, yet less and less people take the opportunity. Those activities and clubs then wither and fade away with lack of participation.
However, on the other side, once those clubs and activities vanish, then opportunities that might have been there before no longer exist to even attempt. An opportunity for socialization vanishes, thereby accelerating the de-socialization.
Very tragedy of the commons type result. There's a communal field. Then some participants start abusing the communal field. Then people accepted of the communal situation previously (because of fair behavior) start pulling back and becoming stingy / paranoid / anti-sharing in response to the exploitive actions of their neighbors. Then the communal resource no longer exists and is ruined for all participants. People who might have joined the communal field use previously no longer have a communal resource to join.