Really depends on where you are in the city; I used to shop at Whole Foods on the UWS and it was lovely, and when visiting this past summer my friend and I visited both the Bowery Whole Foods and the Wegmans near Astor Place and zero complaints with either of them.
But TBH I don't think the grocery deserts he's looking to service are going to be anywhere near where the average HN user lives.
I did all my groceries in nyc via Amazon fresh for the last two years because of this.