In Google Ads, ad extensions gives people more information about your business and make it easier to engage with your Google Search ads. In fact, brands can expect to see a 20% increase in click-through rate on average when 4 site-links show with their Search ads.
In March 2022, Google will be rolling out several new improvements to site-links, callouts and structured snippets.
Above: How to view and manage automatically created extensions in Google Ads.
Above: Serving example for site-links before and after the update.
Source & Full Story: Google.