John Mueller, who works on the Google Search team, responded to a question that asks, "Does extensive Schema markup actually help Large Language Models (LLMs) understand your entity better, or is it just for Google Rich Snippets?" He responded to the question, prefacing it that it is his point of view and "this is not official guidance."
That is being said, John Mueller said on Reddit that it, yes, "it depends." He wrote, "This question will stick with us for the next year and longer, and the short answer is yes, no, and it depends."
It depends on the feature and how the search engine or LLMs uses that feature. John explained that some features really depend a lot on the structured data, like features as Shopping results for pricing, shipping, availability, and other. But in other cases, it is used just to richen up the search results.
Previously, Google has said structured data does not help with ranking, John did not say otherwise in his statement. Google also said in October 2023 and a few times, including structured data is not a ranking factor and said even if you get penalized for structured data misuse, it won't result in a ranking drop but rather the removal of rich results in search. Google did add that it can help them identify product review content.
Here is how John put it, in his own personal point of view:
Some features thrive with structured data (to which I also count structured feeds). Pricing, shipping, availability for shopping is basically impossible to read in high fidelity & accurately from a text page, for example. Of course the details will change though - which is why it's important to use a system that makes it easy to adapt.Other features could theoretically be understood from a page's text, but it's just so much easier for machines to read machine-readable data instead of trying to understand your page (which might be in English, or in Welsh, or ... pick any of the 7000+ languages). Some visual elements rely on specific structured data; if you want it, then follow the instructions. These will vary across surfaces / companies, and will definitely change over time. If you wait, "that type" will be deprecated right after you implement it, so make it easy to get it added when it makes sense for your site.
And other structured data types, well, there's a lot of wishful thinking. Always has been, and will continue to be. Your "best geo insurance comparison site" isn't going to rank better by adding insurance markup.
Microsoft Bing spoke about schema and Copilot usage and there has been some debate around how LLM visibility is impacted by schema and structured data.
Forum discussion at Reddit.
