Structured data doesn’t give you a ranking boost but it can help Google understand your content and thus help you rank in Google, as clarified by John Muller from Google on Twitter. Having structured data on the page doesn’t mean it would give you a ranking boost just like with the HTTPS ranking boost.
John firmly believes that there’s no generic ranking boost for structured data usage. Only thing is that structured data can make the page easier to understand what the page is all about and make it easier to show where it’s relevant such as improves targeting or for the right terms of ranking.
According to John, such development about how Google uses structured data isn’t new. In 2015, Google thought to have decided to use structured data for ranking purposes. But in 2017, Google changed his stand of not to depend on structured data for understanding the web. It’s a different thing that they still consider structured data as crucial.
In Short and simple, structured data by itself is not a direct ranking factor. But it can help in areas like understanding your content, adding rich snippets or cards to your search results listings, click through rates and most importantly helps Google in understanding your content, which might bring a better shot at ranking.
Whether it’s a new concept or not, that only depends upon how you perceive John’s statement on structured data.