>>40194750Every Generation has icon Pokémon. I don't want to say iconic because Greninja is a literal who to the public compared to Charizard. These icon Pokémon are plastered on merchandise, especially in Pokémon Centers in Japan. They'll appear in promotional art for events (I can't remember if they still do this). Of course every Pokémon gets promoted during its debut, but some get far more than others and become one of the faces of that Generation.
Pikachu, Meowth, Lucario, Piplup, Buneary, Croagunk, Pachirisu... most of the Pokémon the characters in the DP anime use icon Pokémon. Why doesn't Ash have a Lucario? Because it quickly became an iconic Pokémon. Piplup was the closest thing to Lucario, but you also have to remember that you can only keep everything so relevant.
Some Pokémon resurge in popularity down the line. There was a time when Mewtwo was seen as distinctly Gen I, but Smash dropped it and it took until late Gen V for it to make a comeback, with 2013 onwards heavily promoting it.
