> If the judge finds that apps and books are so equivalent, then letting the apps require age verification should do no harm -- everyone underage or privacy-concerned will simply go to the bookstore or a library. Right?

That is obvious harm.

The equivalence is that children have first amendment rights (see Tinker v Des Moines) and speech delivered by the internet is still speech.

I have no idea what you're on about but the point is this chills speech, and infringes on the rights of everyone involved, not just underage people.