The problem in the US is that the seller has to use the method that results in them having the least liability in case something goes wrong.
If they choose to use steel or glass, and it doesn't get cleaned properly, and it ends up causing damage, then they might be liable for damages. Their liability insurance will deny coverage for damages because they knowingly used a method that had a higher probability of harm than using new plastic.
I'm sure there might be some way to ensure cleanliness of steel and glass, but it's probably cost prohibitive versus just using plastic, so it might cause the cost of the product to be too high to compete in the market.
Possibly? I guess I assumed there's some cost based reason that plastic is preferred over glass, even excluding for transportation costs due to lower weight and less cleanup costs in case of accidents and glass breaking.
It's probably a combination of all of these things, but the fact that no glass alternatives exist in the market in a similar price range as plastic options indicates there's an overall cost advantage for plastic.
That is more expensive due to energy requirements over simple washes, but if the energy used to do that is renewable then that isn't a big deal. I think the big problem with autoclaving the glass is the time required for heating up and cooling off as thermal shock will break glass. That said, breaking more glass isn't a big deal because it is an inert material. And the sorting and cleaning of glass should be easier and cheaper than ever thanks to better automation and robotics.
If they choose to use steel or glass, and it doesn't get cleaned properly, and it ends up causing damage, then they might be liable for damages. Their liability insurance will deny coverage for damages because they knowingly used a method that had a higher probability of harm than using new plastic.
I'm sure there might be some way to ensure cleanliness of steel and glass, but it's probably cost prohibitive versus just using plastic, so it might cause the cost of the product to be too high to compete in the market.