Particularly GW, but perhaps wargames miniatures in general.
So, wargames got real big in the 90s.
The 70-80s saw SciFi and fantasy emerge and strengthen.
Historical had been around a while, but the 90s saw it became mainstream with hobby shops, toy shops, even LOTR in odd places by 2001.
So if you were 10-20 when you got into it, 70-2000, means your 44-64.
Now, my point…
Where are all the miniatures going?
Into people's collections.
What happens in 20-40 years when the people above fall off the perch?
Bust.
There must be a point that the amount of second hand minis on the market over supplies demand, killing sales of new minis, and thus the industry.
There was the comic boom and bust in the 80-90s, where millions were bought for investment, until people tried to sell them.
DvDs have a beyond saturated secondary market. But new films and TV keep new ones coming.
New minis may always be made, but why buy a new box of whatever, when there are a heap available second hand for sale at a fraction of the price?
Also remember, that many people never get around to opening packets, so a lot of the second hand product may be as new.
The wheels are going to fall off at some point.