Where I live the grocery stores all have groups of 6+ self checkouts that are reliable enough that only one or two might be out at the same time but generally work, all of the 'too many items' issues have been sorted out, and they are in places where people just naturally form lines and take the next free one. It works great and is so much better than checkout lines ever were as one person going slow doesn't hold up everyone else.

Went on a work trip to a larger city and holy hell I understand why people there would hate self checkout. Forced lines, machines that constantly required human assistance, etc. That would suck to interact with regularly.