I think it has nothing to do with children. It is about requiring ID registration for online services so that identities can be tracked. Every time authoritarians want to push another mechanism of control it’s always “about the children”.
Stress causes the body to release high levels of cortisol, which can have various harmful effects throughout the body if at high levels persistently. For example, I have Central Serous Retinopathy due to high cortisol, and have been advised by my Ophthalmologist to reduce my level of stress.
I do prefer to use a headphone jack when my phone is the source of music for my amplified sound system and large room speakers.