JSON-LD structures and organize data in a way that is easily understood by search engines and other web-based applications and is recommended by the W3C. This can help improve the discoverability and visibility of your store and its products online.
JSON Linked Data is used by search engines (including Google Knowledge Graph) to display your products more prominently in search results and to provide more detailed and accurate information about your products to potential customers.
In addition to helping with search engine optimization (SEO), using JSON-LD can also make it easier for other applications and platforms, like social media platforms or content management systems, to access and use the data on your store. It is also the basis of Activity Streams, a format for "the exchange of information about potential and completed activities" and is used in ActivityPub, the federated social networking protocol.