Not all teachers are like you, Hippo.

A lot of extra resources are devoted to children who more obviously need extra assistance, children with learning difficulties, dyslexia, disabilities and so on.

Often, gifted children are pretty much left to their own devices. This can cause problems when they finish work ahead of their classmates, or are generally insufficiently challenged. They can become bored and can be distracted and disruptive.

Sometimes, instead of seeing a child who is intelligent who needs challenging and supporting -- as you do -- some teachers can see a child who is naughty (due to boredom leading to disruptive activities).

Being a gifted child can also be quite alienating and isolating experience. The gifted child, being more advanced than their peers in chronological terms, may find it difficult to make and sustain friendships with their classmates. But then their intellectual peers, the older children, may humour a gifted child but won't really want to hang out with them as friends.

It can be difficult for the child and his/her parents, to deal with these 'problems' of lack of challenging school work potentially leading to disruptive behaviour and a label as 'naughty' child, and also the difficulties in socialising and establishing friendships.

These are issues that may need addressing, depending on the child concerned.