In Sweden we have had a version of self checkout for 20 years in the largest stores, and here it seems to work fine.
Instead of having to scan everything at a station, each product is scanned with a handscanner when walking through the store, and put directly into shopping bags. Then only the payment and possibly a randomly occuring verification is left before leaving the store.
The random testing is usually just an employee scanning three to five items from your bags, and occurs like once every four months (as long as you're not actually stealing and caught).
The best thing is when you've been doing it for so long that the random checks happen, like, once a year. I actually don't think we've had one since before the pandemic.
We have that at a grocery store in my area, though you use an app on your phone to scan with the camera and the "random testing" seems to happen pretty much every time. If I had one of their scanners instead of their laggy app, I'd be much happier. (Though I guess modern handscanners are Android devices with a laser, so maybe not that much better...)