>>23587808People want a sandbox Pokemon game because it is a franchise with a fleshed out world and relatively simple rules with a lot of possibilities. Pokemon Conquest and the Mystery Dungeon spin offs did well, and other genres could be explored.
You could still have gym badges, but perhaps an ability to choose the order more freely. All that would require is some simple scaling ratios. The same scaling could be done with ease in the overworld. Early game has mostly low level and first stage mons, as you progress towards the E4, higher leveled third stage mons pop up. It might even make grinding easier since you wouldn't necessarily have to avoid "early game" routes and could train up wherever you like.
Exploration tends to be one of the biggest draws as we get to discover new regions and dive into different dungeons. A sandbox game would cater to adventuring.
It makes sense, and while it may be different to the core games, it might be more in line with the spirit of the franchise than say a fighting game or first person shooter. Change isn't always bad.