Considering that the developed world has a very high number of middle aged adults and growing numbers of elderly individuals, often in tandem with declining birth rates thusly less younger individuals in general. This is already impacting industries where some media have come to target a loyal, older audience than with a younger one.
This is more of a problem in Europe and North America where you have industries catering to those people and it’s in this environment where geek culture not only grew and flourished but also evolved. Not that geek culture’s absent in places like Zimbabwe or Uganda but the former’s well developed enough to have an industry cater to its whims.
While rising affluence in The Philippines and Kenya would enable geek culture to grow, the already affluent America would start turning inward for want of a better word. That is by pandering really hard to the hardcore fans even if they’re declining in numbers, perhaps reflecting the overall population trends.
Though it remains to be seen if there’s any left of those in the future.