I learnt to play 3 (serious) instruments during my lifetime. Guitar, traverse flute and piano. While I dont play any of them actively today, I would still miss the overall skills I gained from learning them. Motor coordination, memory, just to name two. If I had this AI thing back then, I probably wouldn't have learnt any of them, and missed out on a lot of side effects.

Learning something difficult is rewarding on several levels. To boil it down to just the intended outcome is a rather narrow view of the matter.