You're overly generalizing? Nobody says that ketones "replace" (without any detail) glucose, only that ketones "replace glucose as source of energy". And that

You're overly generalizing? Nobody says that ketones "replace" (without any detail) glucose, only that ketones "replace glucose as source of energy". And that is correct, as the citric acid cycle accepts ketones as input for the production of ATP. Moreover, the body scarcely use any glucides besides as an energy source, so I don't really see your point...