Self checkout for heavy items is usually even easier than normal checkout. With normal checkout, I'm expected to lift the stuff and put it on the belt. With self checkout, I can grab the scanner gun and pew pew them while still in my cart.
Many stores where I live don't offer a scanner gun to customers, only like a small amount of big stores offer it. In self-checkout, we have to move the barcodes over a scanner to get them scanned.
Are your arms made of toothpicks or something? That seems like the most negligible problem to have ever. If you said bags of chips then yeah, because those fuckers are always all crinkled up at the barcode and impossible to scan and I can't be bothered to try to unfold them and get it just right