Even commodities with clear levels of use-value demand like gasoline, eggs, or palladium fluctuate in price for similar reasons, a combination of demand, investment speculation, and, if not always nostalgia, at least some form of emotional connection to a product that seems stronger than its value in use or consumption
In most cases, I believe it is
Arguably the most extreme and exacting (and therefore desirable) grading for a card to get is Beckett's coveted 'Black Label' - which requires a perfect 10 on all four of the company's key metrics: surface, edges, corners, and centering
Japanese cards are often valued for their print quality, exclusive releases, earlier set access, and grading potential, while English cards offer better tournament usability, wider recognition, and stronger resale familiarity in many markets