I agree that the JW demographic consists of mainly elderly people, for two reasons.
(1) I heard from an orthodox PIMI relative the other day that she had attended 25 funerals in the last 12 weeks. The are dropping like flies.
(2) Before I physically left the JWs, I had the, uh-hum, privilege of counting the meeting attendance. 2/3 of those in the hall were 50+. This was almost 11 years ago. Another thing I noticed, both in the hall, and at bigger functions, were the sparing amount of 18-30 year olds. Very slim pickings indeed. It also makes me wonder about the genetic pool of potential mates. Due to the strict rules on marriage choices and sex.
I had a JW relative get married recently. To be honest other than the religion, they are 2 people who never should have got together. I think if they hadn’t of been JW, the whole thing would have fizzled out with been boyfriend/girlfriend. I noticed at a family function I attended that they were sitting at opposite ends the room. The father in law, although he watches what he says, isn’t too impressed with his new daughter in law. But then again, with that kind of environment, and choices, what do you expect.