They have long been popular, but the popularity has increased more than 5x since the pandemic. They were printing less than 2 billion a year before then [1], and are now selling more than 10 billion a year despite shortages, scalping, etc [2].
Perhaps "boom" is a better word for it than "fad". But my point is just that this demand seems to be largely driven by artifical scarcity, speculation, influencers - similar to Labubu.
And eventually prices will hit a peak and I expect we will see demand fall off rapidly.
[1] https://www.pokebeach.com/2021/06/pokemon-tcg-sold-3-7-billi...
[2] https://www.ign.com/articles/10-billion-pokemon-cards-were-p...
Can you really say they're scarce if they're printing 5x as many, by your own words?
Look I agree with you, kids find YouTube videos about really compelling IP really compelling! But that is the story, with Pokémon cards and Labubu. Artificial scarcity, which a bajillion games try to do, most of them failing, doesn't alone move the needle on appeal. It's basically meaningless as a design choice. That's what you mean by artificial, the perception of scarcity, maybe, which everything collectible tries to do, and to me, is not really why kids find it appealing or care of whatever.
It's just the part of the product that you understand. That is what I am trying to say. You don't know why they find Pokémon appealing. You have no idea. You understand the gacha part but it doesn't really matter. It's easier to see this when you try playing really popular Roblox games, it really hits you how poorly you understand appeal.