Pokemon has plenty of freedom. However there is an organized design in which you need to complete linear events in order to progress. I see nothing wrong with that. The areas are big enough and full of pokemon to generally hold the interest of most. A bumper Car on rails was Final Fantasy XIII, that allowed literally no freedom. But when there was even a hint of a chance of exploration it was nothing but a giant empty field (literally an open field populated by a sparse number of monsters). Pokemon is nothing like that, again there are fields teeming with pokemon, caves to explore and waters to surf. Koh I honestly think you're expecting a tad too much out of Pokemon, yes it is formulaic and yes it has been done in a very similar manner generation after generation. But what you need to understand is the entire setup is built around enticing new players and offering them generally the same experience that veterans have had in the past.
Remember how magical Pokemon was the first time you played it as a kid? That's exactly the sort of feeling they want every new generation of players to feel. While some would like a more complex or differentiated style of gameplay most aren't looking/don't want that change to occur. Also there's the idea of profit to look at. If Pokemon were to make any sort of completely radical change to its formula it risks being a tanked game and a giant loss of money. The developers simply aren't willing to take that risk. I think they additions they've put into this game are a great progressive stride and I'm sure we'll see more in future generations.
Remember how magical Pokemon was the first time you played it as a kid? That's exactly the sort of feeling they want every new generation of players to feel. While some would like a more complex or differentiated style of gameplay most aren't looking/don't want that change to occur. Also there's the idea of profit to look at. If Pokemon were to make any sort of completely radical change to its formula it risks being a tanked game and a giant loss of money. The developers simply aren't willing to take that risk. I think they additions they've put into this game are a great progressive stride and I'm sure we'll see more in future generations.