Dude, Z-A isn't a flagship. It's in the Legends line and not a mainline release. The numbers aren't so lopsided when you look at mainline games.

https://www.nintendolife.com/news/2025/05/pokemon-scarlet-and-violet-is-now-the-second-best-selling-game-in-the-series

Also, these are two different target audiences again. Palworld is aimed at us who grew up with Pokémon and now have disposable income. Pokémon is still aimed at a younger audience.