No, that's not true. You don't use eggs when baking bread. (Usually) I worked in a friend's bakery. We went through a lot of eggs. Still, it wasn't an ingredient in 90 percent of what we made. Cakes yes, cookies yes, certain pastries yes. It's very common ingredient when making fillings and frostings. Bread on the other hand, usually no. Basic bread is a mixture of flour, salt yeast and water. And then you expand from that. Sugar, milk, cream, butter, maybe vegetable oil of some kind. Croissants and puffed pastries use a lot of butter.