This is a theory that keeps coming up on the internet. However, roman dodecahedra predate knitting by almost a thousand years. The earliest known knitting was from the 11th century (https://en.wikipedia.org/wiki/Knitting#History_and_culture), while the earliest dodecahedra are from the 2nd century (https://en.wikipedia.org/wiki/Roman_dodecahedron#History)

yarn rots

To doubt that knitting existed in Roman Times is preposterous. Thats like saying they could not weave baskets. Instead, your incredible hypothesis lends credence to recent studies by internet sleuths that indicate history as we are taught may have an extra 1000 years added simply because dates have been mistranslated or misconstrued to read a 1 (one) where there is indeed an I or J symbol, denoting years since the Christ; IOW that that 1999 is actually J999.

I like the idea that there is some sort of thread manipulation going on here, but the videos using this for knitting don't require it to be a dodecahetdron as they only use one hole and five of the bulbs on the verteces.

Unless there's a much more complex knit happening, this isn't the explanation. Maybe with multiple colors or something. Also, if it were used in this common way, it's more likely that there would have been many more made of wood and the device would have passed down from mother to daughter rather than having been lost.