Where PDF file size actually comes from
A bloated PDF is rarely bloated because of the text — vector text and simple graphics take up almost no space. The real weight usually comes from embedded images saved at unnecessarily high resolution, duplicated font subsets, and leftover metadata or revision history from whatever program generated the file.
PrivaPDF's compression targets that overhead first: stripping redundant metadata and re-encoding oversized images to a resolution appropriate for screen or print use, before touching anything that would visibly change the document. For most office documents this alone cuts file size 40–70% with no perceptible quality loss.