[jasong]

In my experience PDFs are mostly used to ensure what you're seeing is what everyone else is seeing. If I sent out a Word or Powerpoint doc, I could be 90% sure someone would have a formatting issue. Maybe their default margins are different or they don't have the same fonts installed. It's a better format for the reader when they don't require edit access.

Google Docs + MS Office has probably figured this out by now, but there's also ton of historical momentum keeping it in use.

As a financial auditor I remember being baffled how people would go out of their way to create paper processes. A spreadsheet that requires confirmation would be printed, signed, stapled to another piece of paper - all so I can remove the staples and scan it to track digitally in our audit software. At least I knew sending them a PDF would come back looking the same...