Fundamentally, why wouldn't cell phones ENABLE more wandering? You can call help a lot more easily with them. That's the crazy thing. They have built-in tracking as well.
Of course we now know that pervasive access vector has been enshittified by Google/Apple and the associated social media mafias to assault children's minds with the unrestrained/unregulated full arsenal of the advertising psychological manipulation playbook.
Parents are simply regressing/withdrawing from the sheer assault of unyeilding economic stress/disruption, negative news floods, information intrusion, dual incomes, etc. That passes on to the kids.
Make sure they can contact you in case of emergencies, make sure they know your address/phone number, and wave goodbye.
(Obviously if you live near poisonous/venomous things then warn them about that, and set some boundaries.)