>>43779525Environment. I shouldn't say Pokémon are worthless, but Pokémon by themselves are kind of nothing. It's the context in which they appear that makes each one worthwhile. Regirock, Regice, and Registeel are cool because you have to solve braille puzzles to reach them, and it's a multi-stage player driven quest. If RSE just had an NPC give them to you, I would seriously not care about them in the slightest. While Garchomp is a cool design, what makes it more interesting is that you can get a Gible after the second Gym in a hidden cave beneath Sinnoh's Cycling Road. So many kids completely missed it, but those who explore and investigate are rewarded.
The very first Cut tree in the series is in Viridian City. Because it doesn't resemble any other overworld object, you feel compelled to interact with it, and doing so rewards you for your curiosity with a Potion. But if that Cut tree didn't have a hidden item on it, it would be pointless and teach the player nothing.
Really, it's how the world conveys its Pokémon that makes those Pokémon feel special. And people associate their positive memories of encountering those Pokémon with the Pokémon itself rather than with the context in which it appears. You'll see people excited that the Regis are back in SwSh DLC, but does it mean anything if they don't have interesting context to back it up?