Most so-called "vegetable oils" were traditionally used as drying oils. This was before the paint industry figured out how to use petroleum distillates in their products in the mid-20th century.

Linseed oil was renamed "flaxseed oil" when the market for stain made with linseed oil dried up.

Containers of vegetable oils typically develop a sticky film on them, due to the drying oil effect.

Maybe I'm not viewing this with the proper historical context, but I don't understand why you are saying the market for linseed oil has "dried up" for non-food uses. Boiled linseed oil, which contains linseed oil, is probably the most common oil based finish for woodworking.

I also looked at this website about "Linseed oil market analysis" [1], which shows that Paints & Varnishes is still the largest user of linseed oil. Then processed foods, then pharma, then cosmetic, then flooring (which is probably also as a finish).

I'm eye-balling the graphs because they don't have a table, but it looks like processed foods is only about 20% of the market. That might be a lot, I don't know, but it doesn't seem fair to say all this excess linseed oil is going into foods because there is no other use for it.

1: https://www.grandviewresearch.com/industry-analysis/linseed-...

... strictly speaking you’re certainly correct that there is still a significant non-food use for linseed and the other vegetable oils. But there were only limited food uses for polyunsaturated oils before deodorization and hydrogenation techniques were figured out in the early-mid 20th century. People might [have] measured out a tablespoon for their cooking pan, whereas today people use these oils prolifically.