Vinegar can be a stronger acid than citric acid and has the potential to damage rubber sealings. That's why many manufacturers specifically advise against it.
Interesting. I’ve used 5% for as long as I can remember, seems to be recommended for that reason. Just never bothered to look into it before as my units haven’t shown any damage. Thanks!
Besides chemical properties, citric acid may turn out to be cheaper, especially if bought in large quantities.
But in the end, I think the cost savings of citric vs vinegar vs rinse aid is negligible. Usage should be about 5mL per wash (matches my experience), and even if you use fancy rinse aid, it is still a small fraction of the costs of running a dishwasher.
Note that the article is concerned about professional dishwashers, they didn't reproduce their findings on household dishwashers. Professional dishwashers are very different from household dishwashers, and they use much higher concentration of detergent and rinse aid.