Two actions are easy to mix up.
Recompressing embedded JPEG images rewrites those image streams at a quality you choose. Text that lives outside the images is copied as stored. Images that are not plain RGB JPEGs are left alone. The new file can be larger.
Rasterizing draws each page as one picture. That is a quality loss. The text layer is gone, so a later search may find nothing. Use it only when you have read that label.
A protected or damaged PDF stops with an error. This site does not unlock passwords. The file you selected stays on your device.