Pokemon isn't based around collecting a fixed number of items.

There's strategy to pick an ideal team. To ev/iv farm if you're really into it.

There's a story, you can battle friends, you can make trades.

Pokemon isn't pog collecting.

Can you understand how one might believe that the franchise with the slogan "Gotta Catch 'Em All" might be about collecting a fixed number of items?

It's understandable, though not accurate.