The last hall I attended 2/3 of the members were over 60. I’m willing to bet in America most European countries as well as Canada and Japan the same will be found in most of their halls.
USA growth -not
In my hall currently, the average age of the elders is 68.4 years old. Youngest is in his mid 40's. Maybe one reachng out for the future. He in his 50"s now. Suspect this may be usual in the USA anyway.
Also too before there used to be a huge need for kingdom halls. Now they are closing several saying they need to consolidate halls so as to not waste resources, like if one hall has more publishers than another..... I used to be and idiot and say things like " I'll believe and support whatever they tell me because its from jehovah, it doesnt need to make sense, we will understand when Jehovah wants us to" aka ""New understanding"" such a bunch of BS
This is how the WT ends... not with a bang, but a (lingchi-resulting) whimper.
(apologies for the bastardized phraseology)