I grew up with Pokemon and I might have some answer for that.
Before Pokemon I had a binder of basketball cards. I collected them but I never had a lot of them. Some of them were cool and shiny, some were split into three parts so they were three smaller cards in one and I liked those as well. Additionally I had a favorite team; the Chicago Bulls and of course those cards were special to me as well. Still though there wasn't much you could really do with the basketball cards and I think probably the same goes with baseball cards right? I had my binder, I'd sit down and flip through the binder, I'd trade cards with others now and then.
When Pokemon came, it took our school by storm. We were all watching the Pokemon anime on TV, we were playing Pokemon on our Gameboy Color units, and we played Pokemon the trading card game (TCG).
Pokemon the TV series told the story of a boy that was about our age. He went on a grand adventure, he was considerate towards his Pokemons and towards others. But most importantly, he was on a mission to catch them all and to become the very best. This idea; catch them all and become the very best is repeated pretty much non-stop throughout the whole TV series and the movies.
So Ash Ketchum (the main character of the first series) becomes an idol for us kids and we want to be like him. We want to become Pokemon masters.
We play the Gameboy game day out and day in when we are at home. Grinding, grinding, grinding. Battling. Grinding. Advancing in the game. The school did not allow us to bring our Gameboys though. However we played the Pokemon TCG a lot during recess. We also played the Pokemon TCG at home because it was fun -- it wasn't just a substitute for the Gameboy game, but nonetheless I think the fact that we were not allowed to bring our Gameboys to school made us play the TCG even more at school than we would have otherwise. But I think it was good that we were not allowed to bring our Gameboys to school. Playing the TCG was a much more social activity IMO.
So we play the TCG and we all want to be the very best. How do you become best? You build the best deck. But there is no single best deck. The strength of your deck depends on what your opponent has in his/her deck. Also the best cards are more rare than the others of course. Additionally the drawings on the cards were awesome and everyone wanted shiny cards which were also rare.
It was a perfect storm. Very very clever marketing.
I think Pokemon contributed a lot to my childhood though and I am happy that Nintendo made Pokemon.
F2P apps that use dark patterns and psychological tricks to extract money from their userbase might actually be closer in nature to Pokemon than I'd like to admit but still it feels fundamentally different. You might argue that in a way the Pokemon TCG was "pay to win" and in a way I would agree but at the same time the TCG still depended on being able to balance your deck correctly and there was always a strong element of randomness that no amount of money could get rid of for you.
In conclusion, with the Pokemon TCG you had both the prettiness of the cards (some kids collected only and never played even) but you also have the utility of the cards in playing a game combined with the best cards being rare, causing many of us to buy as many of them as we could get money for from our parents so that we could build better decks than our friends had and beat them and also so that we could show off our rarest cards to one-another.
Speaking of rarity; I know there are some baseball cards that are more rare than others. I don't know if the same goes for basketball cards but when we collected basketball cards there was never any talk about rarity. Perhaps likewise rarity of baseball cards was not something that kids "knew about"? With Pokemon cards you knew for example that shiny cards were rare because you could tell from the fact that you usually did not get any of them in the booster packs and the full decks contained like one of them or so, so it was immediately obvious that the shiny cards were "special". The Pokemon cards also had various markings that we attributed value to.
Furthermore, with Pokemon you knew the Pokemons from the show and everyone had their favorite Pokemon. For many of the Pokemons, multiple different cards existed, so there were more than just one card to collect for each of the Pokemons that you liked among the 151 Pokemons. Additionally, there were other types of cards that were needed for the game, including "trainer cards" that gave special powers or other advantages and there were "potions" and there were "energy colors" that you needed for attacks. The energy cards were the least valuable because they were so common. Some rare kinds of energy cards existed as well of course but everyone had way more energy cards than they needed. There were some trainers and potions that were very common as well, and some Pokemons that were too. But sometimes you'd find that other kids wanted the cards that you didn't want and you'd trade with them. For example I once traded a common Pikachu card with a kid that was obsessed with Pikachu and he gave me a card that in my eyes was much better, so we both ended up very happy from that trade.
I also remember there was a series of Pokemon cards that were not the TCG type cards. Neither me nor anyone I knew liked those cards, exactly because you couldn't do anything with them other than to just look at them whereas with the TCG cards you could both look at them and play with them. So definitely the being able to play with them aspect was hugely important.