When you insert a pdf as an object, you do not get the entire pdf appearing in your Word document. If the user double-clicks on the object in the Word document, it opens the entire pdf in Adobe Acrobat Reader. For instance, I just inserted a 600+ page pdf into a Word document. In Word, you see the cover page. Double-clicking on it opens the entire pdf.

Word is a word processor, designed to edit text. PDF is a different format, almost like a picture, intended to display text and graphics as if it had been printed. Imagine for a moment that you have a car and take a picture of the car. You can insert the picture into a Word document, but you can't drive it anywhere.

If you want all of the content from a pdf in a Word document, you will need to convert it to Word format. This will seldom give you an easily edited document.