Re: "including Amazon. Again, the details of those contracts are unknown"
"Machine AI, for all its failings, is probably better than the Mk1 Eyeball version. I don't really know why ID parade evidence is considered so valuable. It has been known for ages that it is pretty damn unreliable."
Because it can be used on a much larger scale, and produce a correspondingly large number of false positives as a result.
A manual id parade with 10 random members of the public generates a level of false positives that can be handled, and since the other 9 members are picked randomly the presumption tends to be that if one does get identified it's most likely an error (though I imagine will be investigated).
That's an entirely different proposition to doing a speculative match against the entire past and current driving population of the US. A large number of false positives are extremely likely, and if it's used to find a person rather than merely confirm a suspicion, the assumptions of innocence are not the same.
It's not a matter of automating an existing procedure. It's a completely different test - more akin to looking through a book of known criminals to find a match than a real ID parade, with the vast majority of the faces NOT being criminals at all, which weights the test to favour false positives.