It might be regional. Where I live they just skip the whole call the manager thing and the manager is the one monitoring the self checkout line and is the one you go to to ask for help. Thankfully I don't buy much of anything that'd be 21+ so I don't mind just going to the one open cash register to do that there.
It also depends on the system it's using, as well as what you're buying.
If you're buying anything thay requires ID, or requires being brought in from the back (a fridge, for example), or if you just have a ton of stuff, yeah, don't bother with self-checkout. But if you're just going in to buy a phone cord or a soda, yeah, sure.
And there are some god-awful self-checkout OSes that scream at you to PLEASE PLACE ITEM IN THE BAGGING AREA, or HAVE YOU SCANNED YOUR FREQUENT SHOPPER CARD? and those can piss off and die. But there's some that don't do that, and are set up to actually be user-friendly!
The Home Depot near me somewhat recently changed out their self-checkout machines with UI and UX in mind, and holy shit, it makes so much of a difference. The screen is very uncluttered, high contrast colors are nice for drawing attention to the usual buttons to push, and the buttons per screen (scanning > payment type) change the side of the screen the buttons are on so if you just spam-tap, you won't accidentally hit the wrong button.
Produce all have a code you can just type in instead of having to search. It's right on the sticker for things that have stickers, for things like sweet potatoes you have to look at the price sign and it will have the code on it, then just write it on the bag with a sharpie.
Because the produce that most of the grocery stores, I shop at is loose and I put it in a plastic bag that does not have a label on it. You have to write the number down. It’s not prepackaged generally.
I'm confused too, self checkout is the best thing ever, no social interaction and pretty much equally fast, while allowing for more checkouts in the same amt of space. Though tbf only if done properly. One store here started having them like 10 years ago and there was like a 10% chance each item that you'd have to call over an employee bc the scale didn't work. Haven't had any problems with the ones i encountered recently.
Same here in Sweden. I never go to the regular checkouts because it is annoying to queue. Just scan everything while shopping. Put the scanner back, pay and leave.
Yeah, we've got those in Tesco and it's by far the quickest way to shop. Could even do with a super-express checkout just for those so I don't have to queue at all with the people who inexplicably want to scan a massive trolley of stuff really slowly at the regular self checkout.