Might work some places
Yup, the amazon delivery bot will be in deep do-dos in some rough neighbourhoods. Mind you, human drivers are probably not too keen on those neighbourhoods either. (A truckload of deliveries is more valuable than a single delivery in a bot after all.) I'd imagine the bot has all-round vision being streamed back to HQ, so if something does go wrong, amazon knows exactly how it went wrong, and who the perp was.
OTOH a lot of smaller US cities and most Canadian ones are remarkably safe places. Hereabouts, if you want the sort of goodies an amazon bot might deliver, you can probably walk into any garage along the street and help yourself (and God help you if you're caught - there's soooo many ways people can make your life a misery in a small town).
In these or suburban communities with wide pavements, little traffic and almost no crime bots seem a reasonable idea. So yeah, downtown LA might not be practicable, but there's lots of places it can work.