I think there are a bunch of issues with PDF other than just misuse.
1. Adobe Stranglehold on the platform for a long time. For a long time, you needed Acrobat Reader just to view a PDF, and if you wanted to save in that format, you needed to pay Adobe big bucks to use the format. (Yes there were some free software that worked just as well, however if you are in a business, you probably wanted something official). So a lot of end users, will not bother with trying a PDF, as it would be hit or miss they can view it.
2. Loading Time. Opening the PDF viewer often takes a long time, and not worth the effort.
3. A new UI. Even with integrated PDF Views, it seems the UI in PDF land follows different rules.
4. Too easy to create. If you have PDF writing capabilities. Normally each person will make and publish their PDFs without Ediors, or too much concern about presentation.
5. Convert to different platforms. They save data in a grid format. Just try to copy and paste that data into a Spreadsheet. Nuff said.
6. The PDF File that is a scanned Photocopy of a received fax. It is just an other case that people don't care about how presentable their work is
7. Too much like old paper. We have the data presented in a 8 1/2" * 11" format on our 1920 * 1080 pixel display.
8. Not easily editable. Needing custom PDF software, that is clunky to use to do some simple edits. Normally you use the original format data to fix it. If I have a document on a computer, I may want to edit, notate the document electronically.
9. Needlessly large file sizes. Having the perfect font, and size, handling for scans and impurities, Makes these documents much larger to transfer then what may be needed.
10. They download to your PC, where you need to delete them later. If I am on the Web, I want to see the document, but I don't want to keep it on my PC.
Wow, so much wrong with this....
1. Adobe isn't your only alternative to viewing PDFs. Chrome and Edge can read them just fine. There are lots of third party viewers, with great features
2. Loading time? I guess if you are viewing on a 4GB PC circa 2005 on a platter drive... it blinks up for me in a number of readers
3. Which UI? The one in Chrome? Edge? Third party readers? See #1
4. Too easy to create? What? Page layout is an art form... unless you are simply talking about scanning and making a PDF of images, which isn't really the point of PDF. It's a rather lazy way to compose a document. Still, it's the same for CBR/CBZ comic books.
5. Converting to other platforms isn't the point of PDF, but I'll bite... I have written apps to create CBR files out of PDFs. Some readers can OCR the text and extract that - but if you are using PDF to read dense text pages that don't require layouts, you are certainly using the wrong format.
6. This point makes no sense. PDFs from scans are the simplest form, and mostly used to send documentation to others without upsetting the formatting.
7. The whole point of PDF is for PAGE LAYOUT. It was created to PUBLISH ON PAPER. That doesn't make it any less useful in a pure digital environment (see below)
8. PDFs are not intended to be edited, but there are FORMS.... and those, if handled by the reader properly, work great. Many readers also let you put in text and graphics over top of the original page just fine, if you wanted to make notes or something. The whole point of the format is to preserve the integrity of the page design.
9. Large files are the fault of the creator, not the format. Again, I have written tools to reduce the size of images used as PDF pages into more reasonable chunks. Magazines distributed in PDF formats can have wildly differing sizes for the same issue, depending on the source of those PDFs. For print, images tend to be very large, to preserve the quality.
10. I have a lot of PDFs on my PC. Books, magazines... they save me the hassle of having stacks of books and magazines on my shelves, and even better, they are backed up and always AVAILABLE, even if the internet goes down, or, heaven forbid, somebody removes the original source of information I need to access.
PDFs would be more useful in digital tablets if those tablets adopted the same dimensions as the paper they are emulating... but that's not the fault of PDF creators.
I read a lot of books, in EPUB format. I prefer it over PDF for novels and dense publications, but for magazines like MaximumPC for example, PDF rocks. I have decades of publications in PDF format, as well as hundreds of technical books. They are searchable, and are presented int he same format as the original books. How this can be anything but a good thing, I don't know.