It surely is. My hobby is to look at a person entering self checkout to remember who they are, as I enter the human checkout. I'm usually bagged, and paid whilst that person on the self checkout is still working through their groceries. The professional human is SO much faster than the self checkout.
It's not always the case, but in the vast majority of times it is, so I choose speed over doing it myself.
You can definitely tell some stores try to funnel people into self checkout by understaffing cashier positions sadly :( at the good ones I'm always at the cashier line as well
All of the local stores here have a mobile scanner which you take when you enter the shop. Then you walk around, take the item you want, scan it and bag it. At the self checkout you put away the scanner, register your card, pay and walk away. This is way faster than regular checkout if you have more than 3 items.
I really prefer self-checkout too. There was an initial year or two when the machines were kinda buggy and did that "unexpected item in bagging area" a lot, but you work around it: just never put your shopping bag on the scale. I scan fast and efficiently, and start bagging my stuff while the payment card is doing its thing. And when I bag my own stuff I can be sure the bread is going to be on top.
The only things I run into trouble with these days: 1. when the backend database doesn't have the right info, like some produce type is entirely missing, or the only option is for organic(=more $ and you know darn well you're not going to select that one). 2. Some stores don't use the barcode on the fruit labels, and you scan the label by accident or out of habit because the other store does use those barcodes. Both situations need a clerk to clear them, and that's 90% of the delay.
I wish I knew why Target is limiting to 10 items. It's pretty annoying. I suspect that theft is what's driving retailers away from it, rather than customers hating it.