Considering bathrooms can’t have electric sockets in them here or in France (disregarding the whole having a phone in the bath is ridiculous thing) the only way to charge a phone whilst using in the bath would be to have an extension lead plugged in, which is next level stupid.
Surely the chances of that happening are minimal & most parents will have discussed the whole electricity/water issue?
Can’t be much of a RL risk, all that dropping a phone in the bath will do is ruin a very expensive bit of kit, dropping one that is plugged in would make you eligible for a Darwin Award!