We don't always have the opportunity to even do that.
And even when we do have the opportunity, there are cases where we can't, because the language is untranslatable, for example the North Sentinel islanders: https://en.wikipedia.org/wiki/Sentinelese_language
Yeah, you're right here. My point was more than it doesn't take biological successors to continue traditions. Was more meant to add a light of hope to an all around depressing situation.
If you look into traditional medicine in that area you realize that plenty of the plants they use and used never actually got a proper scientific research on them. It's basically getting lost in front of our eyes.
Probably differs a lot, but the Navajo have a massively developed story-telling tradition to pass on wisdom across generations. Iirc these are symbolic and has moral or philosophical contents, similar perhaps to fables and religious miracle-stories. Encoding information in narratives is highly effective for memorization, and I believe deliberate so. Literal interpretations can be fun, but a deeper semantic interpretation can really unlock ancient wisdom. It's fascinating.
Even if remembered perfectly and consisting only of valuable information, it's amount of knowlege that fits in a single brain. We are centuries past the point when such amount was significant.
You could distribute specialized knowledge among different people, so it's not as restrictive as a single brain. And to be fair, our most valuable knowledge today is probably encoded in few people's brain as well in the form of institutional knowledge. But I get your sentiment, writing down is an immense construction that expands the topology of knowledge by a huge factor.
I was mostly intetested in the kinds of oral traditions, and maybe other traditions to catch knowledge without writing, say, using sculpted / cut figures, etc.
For about half of its lifetime at least, the vedas were meticulously passed down orally with a priest present at its ritual to catch for any errors in word or deed.
A teacher I had of Jewish descent said something similar about his tradition.
It was a lot more common to memorize texts and cultural highlights. In the even recent past most people could recite complete poems and stories by heart.