Is a literacy-last language acquisition model supported by science in any way?

Hi!

My name's Owen and I want to learn Chinese, but I want to run my methodology by other language learners and see if anyone else has had success this way - or if this even makes sense.

I've been doing some basic googling about the greatest language learners in the world and it turns out NONE of them start with a literacy first approach. Nobody is sure why, but the evidence is clear. They all use a methodology that involves listening first, talking later, and learning the writing system later still. Seriously, think about it like this, who gives their babies writing tools while they're trying to get them to say mama or dada? Nobody, because that would be silly. When we learn our second languages for the first time, we don't know any of the words so why complicate the matter by trying to write them? By the time most people become literate in their first language, they're usually fluent. Somehow, I want to try this approach.

Am I just crazy? Does this type of approach work for anyone? Is it even feasible?