frankly I don't think in any even half modern country you can go at it alone. I struggle to imagine how someone would physically manage to evade public authorities here in Germany where schooling is mandatory and any kid not in the education system would sooner or later be caught. There's barely even a place so remote authorities or other citizens would notice you and report you. You couldn't go to the doctor or anywhere really without identification or insurance.
So I think it's less of a function of trust and more simply of modernity, you're not going to escape attention for too long unless you're a trained spy or something