What's the deal with Australia having good child actors?

I am assuming the idea that Australia has the best child actors is more or less true. I'm an American and stumbled into this info when my kids started watching The Inbestigators. Several reviews of the show say some sort of variation of "The show couldn't be made outside Australia." And I see no reason to disagree!

But googling about australia's superior child acting pipeline doesn't really yield much. Apparently you've been crushing this category for well over 100 years though.

Anyway, I'm curious. What's the history? Is this a point of some national pride or would many Australians be as surprised as any American to learn that this niche category is something the country has dominated for a long time? Is child acting just super competitive, do you have more live action kids shows, etc. etc. Broadly speaking, what is different about Australia in this regard?