Because PDF files were not meant to be edited in the way you're trying to edit them.
However, it should be possible to do if you use the Edit Text & Images tool and select all the elements on the page by dragging a box around them with the mouse, or Ctrl+Click them.
Thank you for the help!
I am editing them this way because the file sent to me is paginated wrong - I get a number of pages with one photo and white space - I was trying to consolidate them for ease and eliminate paper waste if my recipient chooses to print the pages.
All the Best!
You'll be much better off just exporting it to Word or something similar, edit it, and then generate a new PDF.
Maybe, but the elements are in pretty big easy to move chunks - it was pretty easy once I knew how to select them!