Indeed. Also very nearly always true with "fake" skeleton leaves used for crafting.

A small percentage (usually enlarged designs of particular shapes) are made with sophisticated latex presses, but most are chemically-stripped and treated real leaves (Ficus and suchlike) because it's simply easier to make them in bulk.

I was amazed by this at first — I bought some for a photography project simply assuming that their flexible, slightly springy nature meant they were artifically-made latex. But no: ficus leaves automatically processed in baking soda, essentially. The latex ones aren't even cheaper.

Well, ficus (ficus elastica and others) are natural latex - their sap is one of the forms of latex that occurs naturally and used to be harvested, but these days latex is harvested from a different plant (hevea brasiliensis, the "rubber tree")

So it's not so much as "the latex ones are cheaper" as "the real leaves are already made of latex, so why artificially make one out of latex?"

That explains why the fake rubber moss I bought has an odd smell and the occasional bit of what seems like a real decayed leaf. Definitely feels like rubber, but if you're saying they took some real moss and chemically converted it to rubber-like material, that makes sense.