The round-trip framing is the correct one and I would add the detail that makes it worse: you cannot tell when it has gone wrong.
A document that loses a tracked change or flattens a numbering scheme does not report an error. It opens, it looks broadly like a document, and the damage is only visible to the person who knows what it was supposed to be. I have sent one of those to a client and did not find out for a fortnight.
The practical mitigation for anyone stuck doing this: send a PDF wherever the file does not genuinely need to be edited further. That converts a fidelity problem into a rendering problem, which every one of these handles correctly. About two-thirds of the documents I used to worry about did not actually need to remain editable, and I had never asked.
That single habit removed most of the risk without changing tools at all.