"AI is a tutor you can message at any time, day or night, for free"
which makes it not a tutor. if it is true that tutors have always made people better students, then those tutors are definitely imposing some limits on how many answers they give you and requiring you to do some thinking. I think you could have premised your same argument by, "copying a smart kid's answers has always made people better students...."
That's why you see the split in outcomes. The fraction of kids who value self improvement are going to get smarter, and the ones who just want to slide by will fall behind.
Nothing stopping kids from asking AI to give you responses like this, it is more than capable. There is always going to be the temptation to take short cuts though.