My 15-year old niece who recently visited her cousins in Australia assured me that the recently enacted Aussie law did not affect her ability to access socials while in Australia, nor has it affected her U16 cousins, who still have their accounts. Apparently the age checking there only applies to newly created accounts.
This is sort of like the illegal-immigration debate. If you’re serious about fixing it, go after employers. Same for underage social media users. If you want to actually solve it, you have to penalize the platforms.