A bag of cassava flour can look fine on the shelf while quietly turning unsafe underneath. I have tossed my own batches over a smell or a clump I would rather not have missed.
The Global Tapioca Market Landscape (Cassava Starch and Tapioca Flour)
My own surplus cassava roots become flour and starch for a small regional market, but the global tapioca market operates on a literally different scale, moving millions of tonnes between Thailand, China, and buyers across dozens of countries every year.