What is "share-sheets" in Android Q? What is this feature and how is it better than the " Direct Share" feature, which was present in earlier versions?
I came across this feature in a recent update to FairEmail and thought of sharing (pun intended :-) 


Getting Started with Sharing Shortcuts in Android Q has technical details but for users :


It's faster than Direct Share 

  The new API uses a push model, versus the pull model used in the old DirectShare API. This makes the process of retrieving direct share targets much faster. 


Android Police says



  .... has new previews for links and images before sharing them, eight direct share targets, and four suggested apps on top, plus it uses a strict alphabetical order for apps....apps can no longer hijack the share sheet by naming their targets as "Add to" .



From my experience in FairEmail, it shows contacts directly in the share sheet, so it makes it faster to share with a specific contact that you've been messaging recently. Favorite contacts become share targets (contacts with photos take precedence, which I believe is a feature from Android 8.1). The same behavior is shown outside of FairEmail, for instance if I want to share a Chrome page, these share targets appear first (without having to go through the mail app) 


Picture below shows the difference. On the left is Share Sheet and on the right is Direct Share 



(click to enlarge)