Both powdered eggs and powdered milk are great for baking. One of the most appealing reasons to use powdered products is the convenience. As a general rule, stored properly they last a long time, and can be bought in bulk. It is nice to know they are always available in the pantry. If you want to bake a cake, you don't have to worry about running out of eggs.
Many people obtain substantial savings in their food budget with powdered milk.
When our children were young, we mixed it half and half with whole milk. I only store what I eat, and I rotate it. There have been times when I could not get to the store, and having a supply of food in the house was a great comfort. How much better to have food in our cupboards than in the store warehouses where we can't get it. Milk and eggs are on the top of my list.