Not everyone can open a PDF. Older phones, some messaging apps and locked down work machines all trip over them. Images work everywhere.
Every device made in the last twenty years can display a JPG, and every messaging app shows one inline without asking anyone to download or open anything. That is why a document sent as images gets read and the same document sent as a PDF sometimes does not.
You lose real things in the trade. The text stops being selectable and searchable, the file gets larger, and the result is no longer valid for anything that requires a document rather than a picture of one.
So use this for convenience, not for records. Send the images so the person can read it now, and send the PDF as well if it needs to be kept or submitted.
For one or two pages, JPG images are the simplest thing to send, and they open on every device. For a longer document, choose Large and PNG so the small print stays readable, or use JPG at 85 percent for a smaller size.
If they only need the words, Extract text gives you a plain text file that opens anywhere. For a scan with no text inside, the pictures are the only option, unless you first read the words with Image to text.
Yes, at normal export resolution. Very small print is worth checking before you send.
One per page for anything over about three pages. A single tall image works well for short documents.
No, the pages are rendered on your device.
Yes. Extract text saves a plain text file. It has no layout, but it opens on any device, and it only works for PDFs that contain real text.