Is it? Maybe with survivor bias but what about all the laid off tellers? Did their situation improve? Walmart grew a lot over this time period, maybe most of them had to downgrade and be cashiers for a generally bad employer.
Also, and this might be a different analysis and topic, but tellers in the 80s had a pretty good job. It was often a decent wage with a pension and good benefits. Maybe on par with a teacher or government employee - granted not the highest pay but good, was considered a “profession”. Compare that to how it’s changed, it’s a low hourly rate on par or only slightly above retail and fast food work, heavy part-time status so as to avoid paying benefits.
I wouldn’t say that was a great example and is likely to be what may happen elsewhere once the routine work is sufficiently devalued.