Let's say you have an allergy to nuts, or shrimps, or some phobia. Life does throw a lot of this at you but it doesn't really help. What helps is following a protocol with controlled doses of exposure to make the body/mind unlearn "DANGER!!!1!11!!" and instead "oh actually this is safe".

Same difference as life making you lug objects/yourself around daily vs a workout plan. You start small and progressively build up to go from here to there. Also you don't stop all physical activity when following a workout plan, it's just that you have a framework to build up.

There may be a thousand ways to do these brain workouts, probably kids would not be too enticed to do meditation or read books so a videogame is more appealing on the surface.

Also I'm not saying this particular game is any good or not in that regard, I'm just saying maybe there's something to it, asking naive questions such as "was this actually intentional design?", and conducting some thought experiment.

Tangentially I'll be the old man yelling at clouds, but I've noticed that games these days are very much not frustrating, probably to cater for the widest audience: compare today's infinite respawn at magic checkpoints with automated difficulty adjustment and no mistake possible change-your-build-tree-anytime and deus-ex-machina health/ammo drops so that you never quite fall short to the likes of Megaman, Mario, Sonic, Gradius, Doom, Ikaruga, Baldur's Gate, Diablo... To be successful these days it seems like games must be pleasing with all frustrations removed, plowing like a demigod through hordes of prop opponents or gigantic bosses made of cheese. By endgame you can even max out all skill trees and be a warrior/wizard/necromancer/sharpshooter/thief all at once.

You can't make a mistake, you can't paint yourself in a corner, you can't lose, you never have to roll back to a savegame 10 hours back or live with your erroneous choice for the next 40+ hours, or, god forbid, start over.