It is for me too in the US. I think it's either specific stores/chains or user error.
Compared to simply walking out, packing everything into your bags right away without needing to scan with either a hand terminal or "repacking" at self checkout is a lot more friction. Didn't really think it would be until I tried a couple of times in a row and it was incredible.
It is NOT seamless. Same issues, and more, but worse service, as is customary in EU.