The social media ban is similar to the logic behind gaming limits in China. The idea is that while the controls themselves are easily circumvented, it gives everyone an excuse to do the right thing.
Parents don't have infinite "control tokens". I only have time & energy to put my foot down about a limited number of things. It is much easier to establish conventions around responsible behaviour if the whole community is behind it.
I am OK with this ban for the same reason I'm OK with tobacco sellers being not allowed to sell to under 18s.
And yet almost anywhere in Europe this ban is completely ineffective as the kids who start smoking get their hands on the cigarettes regardless. It only is a VERY minor inconvenience until they grow 18.
I haven't lived in Europe some years, but I was amazed at how smoking was perceived as more acceptable there.
Being honest here because just telling parents to deal with a societal ill seems very shortsighted and comes from an immense place of priviledge.
For network effect products (social media, drugs, and alcohol), the easiest solution is in fact to use the government to ban the sale of said products to minors. It’s a coordination problem that’s bigger than the family unit.