"Maybe I'm naive, but I think there's no deeper motivation."

Maybe you are not naive. Maybe you are correct

This "real reason for age verification" trope might be just another braindead meme or conspiracy theory

No evidence has been presented to support what these commenters are suggesting

It stands to reeason that anyone who is truly concerned about "connect[ing] real-life identifiers to online activity" would be distancing themselves from using corporate-controlled mobile operating systems like Android or iOS, as opposed to thinking, something like, "I've got a good thing going here with Android and/or iOS and age verification is going to ruin it"