Not standard here, but it's a mix. Same applies to other checkouts: so many people are doing the devil may know what, I'm terrible at picking the fastest queue.

Self check at Sam's Club at other club stores works in a one line per checkout way, where I am at least

Some places it's unclear, like Lowe's home improvement stores. Most people there sort of gravitate to a one-line-for-all-kiosks arrangement but there's often one douchebag who think everybody else is standing there for no reason and cuts in.

well, not in Jordan's hood

Yeah, self-chekout in the 'burbs is fantastic, we have like 4-8 machines and most of the time, at least half are available.

I have the same experience as you and live in a big city, I guess it depends on what country and how up-to-date the hardware is, it used to be like you said but the past 5 years it's been great and I always use it.