Usually people adress the "tear resistance" when they speak of the "durability" of a tennis string. If you are an extreme topspin player or hard hitter, this is logically an important criterion when choosing a string.
Actually for at least 95% of recreational tennis players, durability in the sense of "tear resistance" is completely irrelevant, because their strings break less than once a year and are therefore worn out long before they break. Another aspect of “durability” is therefore much more relevant for them: maintaining the elasticity.
The stringster-app The stringster app helps you to identify the right point of time to actively replace a worn out strings – and to experiment with different types of strings, string gauges (diameters) and tension levels. This is how you can find out how you can optimally adapt your racquet to your personal needs.