I can find no research evidence that structured nursery education like this (with homework) impacts on the medium to long term educational success of children in any way. In other words, it would not matter how much time you spent on ploughing through reading scheme books or mark making homework or whatever, even if your child completes all the activities, the once who does none of this at all will catch up anyway by the age of 7 or so.
Sorry to all those parents and teachers who like to think that a) you can have masses of control over children's cognitive development at age 3, and b) trying really really hard to get kids to mature faster has an impact on their education at 7, 11, 18 or even 21. It doesn't.
It is possible to mess their development up, for example by feeding them crap, not speaking to them much at all, sitting them in front of the TV for every waking hour, and smacking them if they seek attention, but for normal children in normal households, children have a default development speed and you can't really do anything about it.
What does count is quietly letting children potter around copying grown ups at their own pace. It is educationally infinitely more valuable to let a child build a little world out of bricks and then chatter away as they make up a massive involved story about their mini figures as they interact with the world. It is equally more valuable to put them in charge (yes in charge) of aspects of food buying at the supermarket with you, so they have to count apples spontaneously etc. That kind of thing.
It is possible to work through reading schemes and be a fairly limited reader, by the way. Some schools avoid them and use schemes like KRM instead, using a broader range of books. They seem to end up with higher reading ages at 11.
Ultimately pretty much all homework is there for the benefit of everyone except children at nursery and primary age.