https://www.brookings.edu/research/the-effects-of-investing-...
Children are learning machines. I've no doubt that kindergarten radically changes learning, but I don't think this is in a good way.
> Or what is the replacement?
For parents who need kindergarten as day-care (so they can work), some sort of structured activities might be appropriate. I don't have children, so my interest in this topic stems from being punished with boredom for my entire school experience. Some of the alternative education systems might be better, but I've no experience with those. Someone replied to my earlier comment, "Sudbury and Montessori schools offer a model that seems to encourage students to learn at their own pace" [0].
[0] https://news.ycombinator.com/item?id=15693370
To quote myself, "John Gatto says it's better to skip as much of the early years of schooling as possible: some children learn to read when they're 2, some when they're 8, and by the time they're 12 you can't tell the difference. I met a man a few months ago that was traumatized by not being able to "read" on the teacher's schedule when he was in 1st grade. He learned to read eventually, in spite of his school's efforts to force him to read before he was ready." [1]