If you speak to some of the seasoned geocachers you will find out geocaching was quite different in the early days. With only 500 to 700 geocaches available at the end of 2004, some teams would take a drive to another province when two new geocaches were published (find link in forum). If a cache was planted in a park, that was the only cache in that park (and sometimes even in the suburb).
These days it is not uncommon to see 4 or 5 geocaches in the same park if the park is big enough.
In the early days it was mostly 'geeks' and people in the geological industry, who had access to GPS receivers, who played the game. Over time GPS receiver technology has become a lot cheaper and more accessible to the general population. "Paperless caching" was a big term around 2008 as a lot of geocachers would print out the geocache page and then go geocaching. Hints were also manually decoded on the printed out page to find out what the hint was. With the technology becoming more accessible, and put into smartphone the "old" way of geocaching is gone. The numbers in the "old", pre 2008, days was a lot *bigger* then they are today.