The humble PDF is becoming a problem for AI
PDFs are structurally hostile to large language models
There are several free PDF editors that include functionality that Adobe's Reader doesn't, such as merging two PDFs, rotating a page, and many others. This guide will help you choose the best tool for you.
Printing to PDF is a widely available option these days, but what if you have a bunch of scanned pages in JPG format that you want to combine into a single PDF to be shared with someone else?