Google uses structured data to understand what the page is about and catalog it correctly so users can find the information easily.
One reason structured data is beneficial is because of rich snippets. Rich snippets are more specific search results created from the structured data.
Rich snippets usually include more details about the originally searched item. For example, when look up pizza recipes, these three pop up on the first page.
Below the name of each recipe, you can see its rating, how log it takes to cook, and some of the ingredients you’ll need. Those rich snippets taken from the structured data on the page to make it easier for users to choose a recipe.
The more relevant the information is in the structured data, the more likely the page is to rank. The higher a page ranks, the more likely it is to get traffic. This shows how important structured data is for SEO (search engine optimization) purposes.