https://www.webstaurantstore.com/documents/nutrition/999hlmn5308_nutrition.pdf
Hellman's mayo does have a chemical preservative. "Natural flavors" is a bit suspect, too.
Veganaise is full of highly processed and vat-grown ingedients, just like "ben 'n jerry's" has been trending.
Most restaurant stuff is full of compromises.
I think the 800 pound gorilla is cost vs quality, not nutrition. All those restaurants have shit quality, mcdonald's-like production lines, and are a suck-ass eating experience.