I personally prefer to use the self-checkout lane because I want my groceries bagged in a specific way (raw meat in one bag, cans/bottles in another, etc.). It's infuriating when I line up my groceries in order on the conveyor and the bagger just stuffs them in the bags randomly anyway.
I miss HEB sometimes back from when I was a kid. They were trained to bag things "correctly" and was one of the few places that didn't drive my dad insane. They banned plastic bags here shortly before Covid and I have used self checkout since with the nice big reusable ones that I can fill how I want. They would barely fill one bag and then demand another or start pulling out flimsy paper bags that will tear while trying to get my groceries up the stairs. I would bring 3 and it still ended up with me re-bagging it all and dealing with them saying I didn't have enough bags.
Right? That's another pet peeve of mine, the inefficiency. I bring up to 6 bags sometimes and somehow they manage to use all of them for a small haul of groceries, and randomly mixed too (bread smushed in with cans, raw meat mixed with hygiene products, etc.)
I get it, they're not paid enough to be that meticulous; that's why I'd rather do it myself.