While there are indeed some dog with low energy levels, I would say MOST dogs really need some exercise. Bull Terriers, for example, especially when young, often have pretty high energy levels and therefore need quite an amount of attention and exercise.
Not every kind of exercise is suited for any dog.
Some dogs will be completely happy with walks and should not be encouraged to perform certain exercises, such as excessive jumping, long-distance running etc. -because of their physiognomy. That does not mean these dogs just do not need exercise. It just means that other exercises may be more appropriate for them.