It could go in waves, it could be the economy?
We are a bit further along than you, we started camping when our youngest was 1, he is now 19. We went seasonal when he was 11 and the others were 8 and 5. The 19 yo came to camp about 8 or so weekends this year, next year who knows but he heads back to college tomorrow so his tent is down. The 16 yo is with us every weekend, she has her friends that she hangs with. Also she can drive the golf cart now so I am walking more LOL. My 13 yo also has tons of friends at camp and is usually off with them.
Deb and I are starting to get the games out again as we find ourselves sitting alone at the site more. We use to play after the kids went to bed, now we play during the day if no one is around. Works for us.
It will be lonely someday but as of now, we plan on staying put for awhile, we will see if that changes or not in the next year or 2.