We have roughly 55 cards that all have the exact same text. The titles and backgrounds differ among the cards. So I’ve made just one AI with the different backgrounds and all the text as one copy in a layer on top.
Now I can just hide each background layer and save as PDF. But even unchecking preserve editing capabilities, the file sizes let me know that it is still including the images and backgrounds for all the hidden layers. Doing a quick test and deleting all the hidden layers brings the file sizes done considerably.
I was under the impression that saving as a PDF without editing capabilities only saved what was needed for that particular PDF. It seems I was wrong. Do I just have to keep deleting the hidden layers for each copy?
A few boxes down from “Preserve Illustrator Editing Capabilities” is an option to “Create Acrobat Layers from Top-Level Layers”. Make sure that is unchecked. See if that solves your problem! Source citation
As an aside, if you ever have this problem in InDesign, there’s a choice front and center on the export dialog to export visible and printable layers only.