I shop in the morning to avoid lines. But, before self-checkout, they'd only have two registers open, so there was still a line. With self-checkout, in the morning, there's never a line so it's faster.
I like Walmart self-checkout machines better than others I've used, such as at Lowe's or Target (I don't shop at Target anymore) because I only need to put in my pin number, there's no other confirmations. I ignore the rate the store, donation, and print or email receipt questions while I put the groceries back in the cart, those all time out and the receipt prints by default.
I'm happy enough to chat or not chat to strangers, so that was never an issue for me. I'm sorry so many of the younger generation were apparently so poorly socialized, it must be stressful.