One of the things hardest things when creating and maintaining a product is localization. It requires a lot of testing, validation and follow-up. In SharePoint Framework projects it is no different, maybe even a bit harder, as the localization files are created per component. This means that you might have to take care of duplicate localization keys and labels.
When you need to support multiple languages for your SharePoint Framework solutions. It can be a hassle that you have to maintain each and every localization per component in their related loc folder. Official localization documentation: localize SharePoint Framework client-side web parts. Default component localization files If you have one component in your project, this is easy to maintain, but once you will have a couple more.