You get a chalky look to your painting when you use too much white. Painting is not tinting. It is done with thickness and body. The places where paint was used thickly stands out even hundreds of years later. The places that were painted thinly without white paint, and used a number of dark glazes to achieve their effect has many defects in them.
White paint is indeed very durable.
Do not be afraid to use it a lot. Manet, the great french artist of the 1800's, knew this. His paintings today are fresh and bright. He used much white to give his paint a lot of thickness and body. Many paintings that were painted by his contemporaries have turned very dark.