Earlier quoted context omitted.
Sure, if you have time to wait on a huge line. Every time I find myself in a dollar store there’s one cashier serving dozens of angry people lined up to checkout. Whatever deal I might be getting isn’t worth my time to actually wait to pay.
I think this is highly variable between stores. When I lived in Dallas, the line to check out at Dollar Tree was ridiculous, but the one I live near in Brooklyn typically has multiple lines with a few cashiers working. I don't think I've ever waited more than 15 minutes, and typically I wait less than five.
Nowadays, waiting in line is a frustrating anachronism. The exceptions would be higher end stores like Publix that actively guide customers into the fastest checkout lines. But when purchasing a smaller quantity of items, self-checkout is most certainly preferable.