They would only get around geoblocks though.
Also, never underestimate the power of a government to ban VPNs - or just tell the public that only terrorists and paedoes use them.
Shame there isn't any real honesty here about the main factor against these moves, and that is the amount of money these platforms make from allowing under 18s/16s to use them.
Many years ago, I noted that there was no law that required telecom operators (originally just BT) to block premium rate numbers as standard and require the subscriber to opt-in to them (and the services they provided). When I got involved in trying to change that, I met a couple of executives who were quite open about how much their "business model" relied on children dialling 0898 numbers and racking up bills for the parent to pay.
So be aware of who and what you are fighting here. All these platforms will lose revenue if restrictions are put in place.