Yu-Gi-Oh was the absolute king of the school playground. Everybody had Yu-Gi-Oh cards. Nobody knew how to actually play with them, but Yu-Gi-Oh was the ‘cool’ show on TV and everybody wanted the cards. Yet I am not at all surprised that it did not have the lasting impact and broad nostalgia appeal that Pokémon did.
Yu-Gi-Oh’s Western popularity came primarily from the 4Kids adaptation of the anime, which differed in some key respects from the Pokémon anime: first of all, Yu-Gi-Oh was much more directly a show about a product. Yu-Gi-Oh was about the card game. Look at these cool kids playing this cool card game! Cards were iconic because they played prominent roles in the show. Dark Magician. Blue Eyes White Dragon. Red Eyes Black Dragon. Exodia. Slifer the Sky Dragon. Obelisk the Tormentor. The Winged Dragon of Ra. Kuriboh. Summoned Skull. Far fewer would have cared for Dark Magician had it not been Yugi’s signature card. The same goes for Kaiba and Blue Eyes. And for Pegasus and his Toon cards. The relationships in the show were between characters, and the cards were mostly just the tools they used. When I opened a pack of Yu-Gi-Oh cards, all a lot of kids cared about was finding a card they recognized from the show, because it featured in a cool episode or was used by a cool character. The decision to move on from the original cast of characters did the staying power of the TCG no favors.
The Pokémon anime was never that explicitly tied to the TCG. The creatures themselves were part of the emotional core of the show. They were characters in their own right, with their own behaviors and emotions, and they were as much part of the cast as Ash, Misty, and Brock. One of the core messages of the anime is that Pokémon aren’t just tools, and that treating them as such makes one a bad trainer. Yes, the Pokémon used by the main characters were (and are) certainly immensely popular - but this narrative of forming a personal bond with the Pokémon you catch encouraged kids to care about more than just the mascots. This aspect is also a key part of the popularity of the videogames and the continued success of the card game. The show, games, and cards all shared that common theme, yet could be enjoyed entirely independently because one was not explicitly about the other. And for however much people mocked the show for sticking with Ash for so long, that did create an ever-present shared element between generations that Yu-Gi-Oh critically lacked.
Pokémon can make me sob like a child by having Ash part ways with one of his beloved Pokémon, but Yu-Gi-Oh could cut in half all of Yugi’s Dark Magician cards in front of his face and I wouldn’t feel a single thing. Yu-Gi-Oh was just ‘cool’. Pokémon was so much more than that. That is the core difference at play here.
Beyond that, the Yu-Gi-Oh card game itself has become incredibly complex and wordy in a way Pokémon has been able to avoid. Pokémon is still as approachable as it ever was. Yu-Gi-Oh decidedly is not. The odd dissonance between cutesy anime girls, dark fantasy & sci-fi elements, and silly joke cards that was once a fun curiosity now just feels like whiplash - yet the overall art direction somehow feels bland and uniform. Pokémon manages to still inspire wonder with new creature designs, new illustrators (side note: Yu-Gi-Oh not crediting their artists is inexcusable and in itself enough reason to turn me away), and stunning full-art cards. When I look at a new Yu-Gi-Oh card, I just see another Yu-Gi-Oh card.
I am absolutely still nostalgic for that original era of Yu-Gi-Oh, back when it was undoubtedly the king of the playground; I just don’t have any interest in getting back into collecting it.