Just a fun little fyi... No past tense is needed on this, and one need not reference history when it comes to Native Americans and washing hair with botanicals. We're still here, and we still do.
Not all the time, unfortunately, and not all of us... Too many of my relatives have been so thoroughly colonized that they've lost the knowledge of their Ancestors.
But also, homemade plant-based washes take a lot of time and effort to make, while most of us are busting our butts just trying to make ends meet. So in the US, bottled shampoo is typically for regular use and traditional washes are for treats, special occasions, and sometimes for traditional spiritual rites.
Now, I can't personally speak to what happens in South America, but considering how many areas don't have regular, reliable shipments of supplies, and how much plant life abounds in less developed areas, I think it's safe to say there are many indigenous people who still use traditional ways for many, many things.
And frankly, I struggle to find commercial shampoo & conditioner that can do all my hair needs. If I had access to yucca plants, I would absolutely try traditional yucca root washes and see if it worked better. My hair is just very different from European hair, and I'm only half Native.