All kids are different when it comes to reading, or learning anything else for that matter. My kids were sight reading words at 3 but my oldest did not start reading really well until first grade. In first grade they had an intensive language arts program for 2 hours a day. However, he is not that interested in reading. He prefers math and science. He is on grade level for reading and way ahead for math.
Another one of my sons is learning to read now and is still in preschool. He is obsessed with learning letters and writing words too. I think he will be my big reader.
I know that the reason there is such a push for language arts here in Virginia is the SOL tests (Standards of Learning). All students must take them starting in 3rd grade and if a student can’t read well by then, they won’t be able to pass the tests and the schools will be penalized.
I think as long as they are on target for their grade level, they are fine.