>>12166479How else would you program it besides having an NPC for it? I for one wouldn't want to clog up my menus with yet another option I'm not going to use often, or my bags with an item that's mostly going to sit there. This way, the feature stays out of your way unless you need to use it (which really isn't that often), plus it's entirely reasonable as something as an NPC funtion.
Think back especially to R/B, which set the precedent. Memory was at a premium (missingno, anyone?), as was bag space. Having an NPC do this was probably the best way they could find, and there's no reason for them to abandon an elegant solution like that in later gens.