How are the data - Search queries, Clicks, Impressions, Sessions, Bounce Rate, and Average session time data shown on the Readability score report will be useful for a Content Writer or the user?

Analytics Data for Content Engagement Metrics
After writing content and adding to website pages, the businesses need metrics and a way to measure the success of the content on the web page. 

After writing new content to the web page, the website visitors can spend long time on the web page if the content is good. If the bounce rate is very high and average session time is low than the previous values before content change, then the new content is not performing good and need some content change strategy.

Search queries gives how many keywords used to search by the user to show up on the Google search results. This way we can relate what keywords are driving traffic to this content page.

Impressions and Clicks data give how many impressions this page appeared on the search results for user queries, and how many clicks that the user come to visit this page respectively. We can correlate these two data before and after the content changes on the page for traffic flow to the web page

Sessions, Bounce rate and Average session time helps the user to understand whether the new content helps visitors to engage on the web page or users leaving the page quickly after new content.