Ten years is definitely a nice milestone.
Some weeks ago, I started a thread asking where everyone was because forum participation seemed, to me at least, to have fallen off a cliff. As you relate above, we seem to have lost people to various golf oriented pages in social media sites. What some studies by marketing companies are showing though, is that when or if people get tired of social media sites, they drop away completely from internet participation about whatever the subject might be.
Oddly, they don't seem to return to old fashioned forums like this. I don't understand why, but I suspect it's because participating about your hobbies on a social media site is more intense, not as polite as it would be here and it becomes a constant barrage. Maybe they get burned out and even a return to a gentle effort in a forum is unpalatable.
I still think the forum concept is a stronger platform for enjoying subject matter, not to mention making great friends. As usual, I seem to be in the minority.