That's a tough question for me as I simply don't deal in new cards that come out. I got away from them as the card companies started concentrating more and more on the lottery aspect (Inserts, signatures refractors etc...) of card collecting an got away from what made it a great hobby BEFORE there was serious monetary value.
Unfortunately you can't put the genie back in the bottle. It simply isn't possible for the card companies to go back and refocus on putting out sets that teach about the history of the game, while being a reasonable task to try to assemble through the buying of packs.
I feel like through pricing and this chase of high dollar, artificially rare, cards kids have been pushed to the side in the hobby. Anyone with any brains understands you HAVE to keep kids interested to maintain the long term health and growth of the hobby.
All that being said I think the market for older cards (especially pre-war) will be fairly consistent. The kids who do get into the hobby eventually get curious about what came before (that's what happened to me) and adult fans of the sport, as they become more and more well off, like the history of the older material and the idea of collecting the greats of the game from their childhood, their father's childhood and so forth.
When I was a child coin collecting was a HUGE hobby. While it obviously hasn't "Died" it is nowhere NEAR its heyday anymore. Card collecting will likewise never die, but I don't see the future as incredibly bright unless the card companies find a way to de-emphasize the potential monetary gain of new cards and somehow restore the focus on the love of the game, it's history, and the little kid buying packs at the corner store trying to complete his set.