It depends on the difference, because genetic differences aren't always beneficial. The Hapsburg Dynasty's Charles II famously had an inherited birth defect due to the heavy inbreeding[1] among the ruling class, for example. It was of no value to anyone.

The true reason for valuing lineages is more about social rank/class protectionism.

[1] https://www.smithsonianmag.com/smart-news/distinctive-habsbu...