I remember Walmart introduced check-outs way back, and it was clunky, etc. They got rid of it.
Home Depot was one of the earliest adopters of it as well, and moving to the 'burbs' in Toronto in 2013, I did alot of home repair work, and have done so regularly, thus got really used to the mechanics of using the self-checkout. This was the first of the new generation ones I saw. Around this time too, I think Metro had it too which I had trouble (slow, clumsy) using.
Thereafter, Walmart re-implemented it and to my surprise, it was similar to Home Depot's. By that time, I was a pro at handling it. Including at Walmart and their veggies. After not shopping at Metro for awhile, it too was a breeze (no more clumsiness bagging, looking up produce, looking at the screen). This says to me, my self-checkout skills improved alot. So when I see a Shoppers, I prefer self-checkout when there is a line. Often I'm just picking up 1 or 2 items, and for the longest time, going back 10+ years, I thought Shoppers would be the most beneficial for self-check out since you have alot of slower older people, buying all this stuff, people trying to get flyer discounts, etc.
So regardless of cashier jobs (sorry, just because you implement minimum wage, all else isn't equal), I use it when I can.