Most of the toys on the marketplace today are made from sort of vinyl. Why? Because it is a byproduct of petroleum and therefore available in abundance. You can pick out vinyl by its strong plastic like, or sometimes, burnt smoky odor. Any of the super soft materials like jelly or the pink flesh-like feeling ones are all vinyl based.
Latex, although much cheaper as a raw material, is an organic substance and will react with oils, mild acidic substances, even water and body fluids and will quickly deteriorate. Anyone who has had experience with latex toys knows that you can’t expect them to last for very long.