From a purely technical point of view (of budgeting for and creating an advertisement that encourages people to look after their mental health by doing something they enjoy), extraverted activities are orders of magnitude easier and cheaper to make advertising material for which I think is most of why there is a ridiculously heavy bias towards that.

I do think it's extremely lazy to not cover small group/solitary activities but can understand why it's less done when considering budgetary constraints.

And another thought that just occurred to me partway through coffee #1, it could be that most/all of the people on the advertising teams are extraverts themselves and so are hyperfocusing on the ideas that would give them fun and don't have the imagination to consider any other type of fun.