I think the parallel to look at is comic strip art. There are a dozen classic strips that still retain value and are appreciating, such as Peanuts, Raymond Flash Gordon, Krazy Kat, Little Nemo, etc.
But former superstar strips like Pogo are fading.
Other than the classics I listed above, the strips that are appreciating are the more recent ones such as Calvin & Hobbes. Based primarily on the fact that the fans of those strips are reaching peak earning age. Now, C&H May achieve classic status like Peanuts, etc but it’s too soon to tell, IMHO
Comic art is probably going to go the sane route. Some classic stuff will hold on and appreciate, but a lot of stuff that we may think is top notch right now may not hold onto its value in the long run.
I think something like Preacher Art would be a good example. It’s hot right now, but will it hold on to this level in 10-15 years when the biggest Preacher nostalgia collectors liquidate their collections and the TV show has been off the air for years?
Walk Kelly’s Pogo was considered the pinnacle of comic strip art at one point. A true classic. Now, you can by 3 Pogo strips for the price of one Garfield.