According to the article, the wait time is 10 years, which is not ideal, but far from 39 years. No idea how is it with minors, but even if only adults can start the process, he would've been a citizen by the time he was 28.

[–] abff08f4813c@j4vcdedmiokf56h3ho4t62mlku.srv.us 7 points 2 weeks ago

Yeah, it's really strange that Sonny's citizenship application is still pending after two decades.

Reasons are mentioned in the article:

I ask Sonny why he thinks his own application for citizenship has taken over two decades.
"It's racism," he replies immediately.
At one point his file was lost completely, and he has now been told his case is "pending".

Insaf's case is similar.

"I arrived here at nine months old, and maybe at 33 or 34 - if all goes well - I can finally be an Italian citizen," she says, exasperated.
Her parents finally got Italian citizenship 20 days after Insaf turned 18. That meant she had to apply for herself from scratch, including proving a steady income.

You're correct of course in that a big part of the problem is that it seems only adults can start the process, as per https://immigration-italy.com/how-to-get-citizenship-in-italy/ there aren't separate provisions for minors to naturalize, the usual naturalization pathway requires things that normally only adults or emancipated minors would be able to provide, and minors whose parents naturalize are automatically naturalized too.