Yes, they certainly do. Most blanc de blanc Champagnes, being lighter and more elegant than other Champagnes, are excellent aperitif drinks. Brut Champagnes are dryer than extra dry Champagnes. But brut Champagnes can vary widely on how dry they really are. Extra dry Champagnes are slightly less dry than brut Champagnes, but they are more dry than sweet.
Most Champagnes are far too dry to serve with dessert.
Brut Champagne, for example, or even an extra dry, will taste bitter, harsh, and acidic with sweet desserts. If you are determined to have a Champagne with dessert, by all means use a demi-sec Champagne. A better choice with dessert is Asti from Italy, a sparkling wine that's made to go well with desserts.