This is a common misconception. It probably does not match your and others' experience simply because it is conventional wisdom, and most people are taught to do this. But just because most people do something a certain way does not make it the most efficient way.

There are a number of reasons why you would want to focus on input early on. For starters, with very little exposure to a language, you have very little idea of what it is supposed to sound like. Not just pronunciation but word choice, grammar, and phrasing as well. So when outputting early you will make your best effort attempts, which are almost certainly going to be incorrect. Odds are these poor "best effort" attempts will stick as muscle memory and continue to be bad habits well into fluency, if you make it that far. I'm sure you've encountered many foreign speakers in English that are very fluent but have poor pronunciation or use incorrect grammar.

I've never heard that "producing" a language is more efficient to learning it than "consuming" it. How can you learn anything by producing it without having "consumed" it first? That's not learning, that's inventing, and you don't want to be in the business of inventing language unless you're William Shakespeare. If you're interested in learning more about this idea, check out Stephen Krashen's Input Hypothesis [0]. In particular this quote from the Wikipedia article is salient:

> Talking (output) is not practicing. Krashen stresses yet again that speaking in the target language does not result in language acquisition. Although speaking can indirectly assist in language acquisition, the ability to speak is not the cause of language learning or acquisition. Instead, comprehensible output is the effect of language acquisition.

[0] https://en.wikipedia.org/wiki/Input_hypothesis#Input_hypothe...