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.