Mumsnet CEO is apparently on their advisory board, which more or less explains it. They just want something cheap they can tell someone else to implement to win the votes off concerned parents. It doesn't matter if it works, it just matters if they can carve out votes in 2029 for it. UK has a relatively long standing tradition of fucking itself over in order to win a single election (e.g. the Brexit ref).

Its particularly frustrating cos they ain't even done the OAuth properly like the Aussies have taken a pass at. Could even put an NGO as a shim in-between to protect privacy. But noOoOo, we'll ignore all the tech advice, do something shit and then follow it up by trying to "ban" VPNs when it clearly doesn't work, because we're thick.