Hi
Im sending this message for adobe acrobat reader user interface and commenting on pdf file.
Previously there was a PDF app named "Repligo PDF reader".
Later it was discontinued.
If you can check, the user interface of Repligo PDF reader was awesome.
There was a button at the top for viewing all bookmarks.

With one click, all comments made on pdf file could be seen in sidebar.
Pdf file opens very fast.
Search option for a keyword was awesome.
All search results were accessible quickly.
Annotations options were awesome.
Kindly go through that apps features and consider adding them in Adobe Acrobat reader.
Thanks for reading my message.