Disclosure: I'm one of the survivors, as are both of my kids. I started classical cello lessons in 4th grade, and just kept going, though 50 years later I'm a jazz bassist. My kids started on string lessons, and are both good classical musicians today.
In my view there's no silver bullet that will reduce the attrition rate for kids learning to play music, and I think no reason to believe that classical lessons are even significantly better or worse than any other approach.
As mentioned in the article, being part of a musical family helps, but is not a silver bullet. The musician parents tend to be more laid back about it, more patient about progress, less focused on competition. Very few of them express an interest in their kids pursuing music careers, though it sometimes happens anyway. Most just talk about the lifelong enjoyment of music.
Every instrument has a unique learning curve. Yeah, the violin. Guitar and piano are no easier to play at a high level, but can at least produce a decent tone from the beginning.
One thing that might help a bit is starting kids younger, before they are old enough to be self conscious about sucking. Those kids also get chances to play with other kids, and everybody applauds.
I have no aspirations of a music career, but I do get paid to play, and my main band has a small but loyal following. If you have a day job, as I do, you can pick and choose among different aspects of the music business. For instance I have no interest in making or selling recordings, touring, or being famous. I do expect to play with fairly high caliber musicians.