So they are offloading checkout onto the consumer via dash carts. There's no value proposition for the consumer unless somehow they are able to lower prices by not hiring cashiers.
Maybe one advantage is it finally stops customers from asking to pay half with a check and half with cash for a $2 item in certain places. There's an entire Walgreens I avoid because that's happened 3 times already.
That's the only place where it has a step I don't need, it wants payment because capitalism, so there's a bunch of touch, tap, touch again sequences to get from it knowing what I took to being satisfied that I have exchanged money for goods and then I can go.
One thing I barely noticed at all until after it had happened was the removal of cashier operated checking out from most of the store. Ten years ago there were maybe 20 such checkouts, then sixteen after they added some self-checkout features - obviously rarely all manned but they existed. Today it's four, and often none of them are open, because almost nobody stands in a line to have somebody else scan your shopping, why would you?
Instead there are three distinct self-checkout zones. First, the one I use almost always, for people who have scanned their purchases already. There's nowhere to put anything, because these are just vertical terminals for taking payment. Then, short order terminals, a small built-in scale is provided so that you can buy say, lunch, but there's nowhere to load and unload a whole trolley of groceries. Finally the big shop terminals with lots of dedicated space for you to transfer from a trolley onto a scanner and weigh scales, then to your bags, this takes up most of the space previously occupied by cashiers.
If you've scanned everything you can actually use any of these areas, because the terminal understands that you've already done the whole job, but unless it's super-busy it will be easier to use the dedicated area for people who've done all the scanning.
A decently trained human can scan & bag far faster than I can at the self-checkouts.
The self-checkout machines are also sometimes buggy. Our local Safeway's self-checkout was extremely particular: if you scanned the next item prior to the computer registering and processing the weight from the previous item being set down, it would error out and require an attendant. That processing was quite slow — so you needed to lag yourself / rate limit yourself, so as to allow the machine time to think, before proceeding. I eventually figured out the cadence to go, such that I could avoid the error … but humans just don't have this issue.
Items too light to be detected just always error on some of these machines.
Here are the reasons I prefer the manned cashiers:
The line at the manned cashiers is often shorter than the line at self-checkout.
Scanning everything myself is a pain.
If something goes wrong or I make a mistake, I won't have to put up with being accused of shoplifting.
The time savings from self-checkout is usually minimal-to-nonexistent.
I get to have a little human interaction.
Since there's no discount for using self-checkout, I'm effectively paying extra in order to do more work.