Boring answer but besides a few quixotic individuals who reserve high value digital real estate for loved ones JIC, most online accounts created on behalf of those with little agency (babies, pets, etc) were created exclusively to funnel more attention to the attention-addicted creator, whether via cute photos or puppetry.
But these accounts are abandoned once the attention well dries up. The account credentials are soon forgotten and within a few years the accounts are garbage collected by inactivity pruning algorithms, or hacked and disabled. In any case, they’re long gone by the time the kid comes of age.
E: So basically zero. These pampers influencers simply created a new account.