Cats are hunters by instinct. Yet instinct can’t teach them exactly how to hunt specific types of prey. That’s why older cats (usually the mother) may need to teach kittens how to deal with different types of prey from lizards and mice to birds and flies.
Each type of prey behaves differently so it only makes sense that cats need to teach each other lessons for hunting each type. This shows that cats can learn when they want to. The reason why they never seem to learn from people is because they don’t want to. It’s as simple as that.