It won’t stop kids accessing inappropriate material. Just like they access vapes, films and drugs. Teenagers will find a way.
An older sibling will grant access. Or a parent won’t care and will allow access. Or they will get their tech savvy friend to get round it. Or use a stolen credit card. Or their parents ancient email address (which is linked to their parents finances). Or the dark web. Or 18 year old brother accesses porn, 14 year old records using his phone. It’s not hard.
Or the techie kids will help their peers. The top three or four kids in year 7 IT are very competent, never mind year 10.
Wait until drunk naive 18 year olds upload their passport and end up being blackmailed. Has that been risk assessed?
Or 13 year old goes into the dark web and accesses more than porn?
Or parents bank is accessed due to a child using the parents ancient email address?
This is about controlling what adults can access hidden as a concern for kids. If they were concerned for kids there wouldn’t be a rape gang scandal as authorities would have acted long ago. And rapes wouldn’t be rocketing in number.