Different metals are in use, at different temperatures, and inhalation rather than ingestion.
Vape coils are typically kanthal, the same material as in my ceramic kiln wires, and were not designed for food/smoking purpose before people started using them for that.
I'm pretty sure you're not allowed to sell a pot made out of unsafe materials and market it as a cooking implement. I'm also quite confident that it's technically possible to make a safe vaping device. So the issue would be a lack of regulation?
Definitely, there is a lack of meaningful testing and regulation. Also, everything about vaping is too new to know the long term effects on human health.