Aneek Bera:
why do we add labels to pods?
Christopher Town:
Labels allow selectors to determine which pods to group (LoadBalance) behind a Service.
Mohamed Ayman:
One use case for selecting over labels is to constrain the set of nodes onto which a pod can schedule.
Label selectors can be used as a quick and easy way to debug pods.
Anand Karwa:
This article should give you more details from what others have shared
https://www.magalix.com/blog/why-it-is-important-to-use-labels-in-your-workloads-specs