From a legal viewpoint, selfcheck mistakes make you a criminal, and the stores make money for going after you for a settlement. Its already happening for customer mistakes to be prosecuted and settlements (walmart is the biggest culprit).

I'm buying groceries not getting into a possible legal issue, I'll avoid self checkout on a cart, maybe on 1 or 2 items self checkout is ok'ish.

Plus I feel using self checkout puts people out of jobs.