Regularly? That means that some nontrivial fraction are guaranteed to burn. I think you mean that it happens at low probability but is eagerly covered by media.
In any case, the fault is almost certainly either physical abuse (which has nothing to do with accessibility/modularity) or simply bad chargers (which better access would actually mitigate).
In any case, the fault is almost certainly either physical abuse (which has nothing to do with accessibility/modularity) or simply bad chargers (which better access would actually mitigate).