Look, I get that this capability is super useful on shopping sites, and I rely on it practically every day.
But, I also build enterprise applications, where Chrome simply would not ever understand or know what would be valid choice.
I do, though; I built it. Invoice Numbers / Pre-Validated Travel Dates & Locations / Pre-Validated Locations / Pre-Validated IssueID that are so esoteric, we have built custom autocomplete that provide additional relevant information / Pre-Validated Users where the number of valid "John Smith"s number in the 10s, and additional meta data must be provided to differentiate.
Application developers need a reliable, durable way to tell the UA that a particular field should never be autofilled or autocompleted. The spec says this is autocomplete=off. Just do that.