People should not be able to misrepresent themselves on the internet, it may have been safe in low volumes but it is scary now and will be outright dangerous as a modality in the hands of AI agents. If you think teen mental health is bad now, wait until social media campaign capabilities previously only available to nation states fall into the hands of ordinary school bullies.
Maybe age verification isn't the way to mitigate this obvious risk, but there has to be something that can be done to stop rampant sockpuppeting.