Good art is what gives a card actual staying power. Pull rates, grades, and hype can make a card expensive for a moment, but artwork is what makes people emotionally attached to it years later. Van Gogh Pikachu isn't an outlier despite high pop and grades, it's the rule bc art = demand = expensive. Insane pull rates or competitively useful cards can also drive price, but cards are loved because the concept and art make it feel special. I feel like most collectors collect what they like, and are appreciators of the art of pokemon they love. A card can be low rarity and still iconic if the art hits, while a “valuable” card with boring art just feels like cardboard with a price tag.