Adobe "bounce" metric shows 70K bounces. Time on page "bucketed" and "granular" metrics show 20K visits with time on page from 1 second to 30 minutes. If only 20K are actual visits then why does the original "visit" metric show 90K?
Based on my understanding, if the visitor is landing on your site then the 1 Visit will be counted for that Visitor. But, after landing on your web site, if no other server call triggers then that Visit will be considered as Bounce. However, if a visitor lands on your site & performs any action link linking on a link then that Visit will not be considered as a bounce because now there are more than one server call which has fired in the visit. For more information on bounces, you can refer to the below link.