It depends on how it’s prepared I suppose. If you only have bread dipped in egg and served plain i wouldn’t call that sweet. But by adding milk or cinnamon or other such flavourings to the egg mixture it can become sweet, as well as using a sweeter bread such as brioche. This is all without mentioning the traditional toppings for French toast such as powdered sugar or maple syrup. Though, I’d hardly consider plain bread dipped in egg to be worthy of the title of French Toast, it lacks the necessary dressings to be considered anything close.