Most people just use pencil + paper, or notepad/note app on phone. Never have I seen people actually use technology while shopping unless it's a typed out list.
Yep I agree. I've tried lots of to do lists, apps, etc. and always keep coming back to the pen and paper stuck to the refrigerator. Siri adding stuff to notes through voice rec worked pretty well, but it's a gigantic hassle to be cruising through the grocery store constantly turning your phone on and off to go through the list.
Although nicely executed, I really don't see Dash being more than something a gadget freak uses for a few weeks and then sits in a drawer forever. Also doesn't help that the area for Amazon Fresh is so small too.
In fairness however, my wife and I use grocery lists on our phones all the time (though it's only two steps, not the OP's 7: (1) "put peaches on my grocery list" (2) confirm).
So, I built an app for exactly this type of scenario[1]. My wife would ask me to buy something, and then forget, so she'd send an updated email. And then an updated updated email.
And then possibly a text message. Of course, it goes from being 2 things to 10 things quickly. And then I'd have to deal with actually keeping the list orderly and constantly checking what I did have in the basket already (more difficult with 20+ items).
So, I wrote an app. It was funny, building a "twodo" app. But honestly, I just needed something that worked.
I mention all of this because it did start with trying to use what we already had.
"Number of steps to scan grocery by phone"
Most people just use pencil + paper, or notepad/note app on phone. Never have I seen people actually use technology while shopping unless it's a typed out list.