Being new to the sport i can see how easy it is to let it slip away in a sense. I have only been caching for a few months but have noticed that it gets hard to find time to go caching, outside of school, homework, practice and everything. I dont think that the sport will ever get too large scale to be playable for the reason that people come in and out of the sport.
As for too many caches i know around my home there are A LOT. in fact i think the nearest cache is less than .15 miles from my front steps, not to mention the closest 25 which i believe are all under 2 miles. With briones park a 5 minute drive away containing roughly 30 caches i dont think i will ever run out! hopefully the area wont continue to get over saturated, i would like to place my own cache soon. I think that is part of the beauty of the sport though. The places to hide caches are nearly limitless. Even though it seems like there are a lot around here its always possible to find enough room for a film canister.