No eggs are not made fluffier or better by adding milk to the scrambled eggs.
Actually when you add milk to your scrambled eggs the milk when added to the scrambled eggs makes the scrambled eggs colorless and more rubbery which is not very good.
The milk may add a better taste to the scrambled eggs for some people but I personally don't like making scrambled eggs with milk.
My school when I was in Elementary school used to serve scrambled eggs for breakfast and they used milk in the scrambled eggs which made them rubbery and I hated them.
So if you want the best scrambled eggs you should avoid adding milk to the scrambled eggs.