....My father told me when he was a kid it was 50% SxS, 30% pumps and 20% autos and no O/U. When I was a kid....
....Now it is....
One way to look at it might be, the SxS was the camo and black plastic of the day. Everyone starts somewhere. A shooter of anything might be more likely to get into an antique or classic, if they weren't discouraged early on.
There are way more shooters today, for a relatively fixed number of SxS's. There's bound to be a niche market, even if it's not the appreciating investment that some seem to hope for. Even today with high supply, some sellers are able to find markets, and there will be people saying that they are so glad to have bought at 2020's prices.
The US has a better chance of future appreciation for fine SxS's, than the next generation in the UK. It's a real time lesson in how to discourage a population, primarily by pricing something out of reach.