Are you all for real about this? I buy coffee, soylent, various hard to find canned goods, and other things all the time off Amazon.
Right now I’ve only seen it in electronics but I don’t buy much food that way. Amazon fresh is a different thing (all sourced / sold by amazon) so probably not a problem. Likewise oddball stuff (a low volume brand of tea) is unlikely to be worth counterfeiting. But mass market goods definitely are and the baby food example, while not amazon, is an excellent cautionary tale.
I honestly miss being able to go to a unique store to buy things - that way you could look at what you were actually buying and (maybe!) find something better for what you're trying to do.