As said it’s possible to edit PDFs but of cause it’s a pain in the ass because that format doesn’t have a lot of semantics information about the original source. PDF doesn’t understand how to reflow text to the next line.

It’s a bit like having a Photoshop file with many layers, saving the image as PNG, sending that PNG to someone else, they open it in Photoshop and than complain about why Photoshop is trying to prevent the PNG from being edited.

You can edit the PNG but it’s a pain in the ass because the original layer information is lost. Same with PDF. Nobody ever tried to prevent anyone from trying to edit PDFs but of it’s more that fixing some minor typo is certainly is a pain in the ass because thats not what this format was designed to do.