I don’t think GP was asking for people on Hackernews to invent a general purpose, greener alternative to PVC.
I think they were asking whether there’s an alternative that hobbyist could use for these types of projects.
For example, there might be a material that’s significantly greener and a bit more expensive — enough so that a large scale project couldn’t justify the economic costs (i.e. it wouldn’t be a general purpose replacement for PVC), but such that a small project hobbyist would prefer to have that melting in their garage shop instead of PVC.
I think they were asking whether there’s an alternative that hobbyist could use for these types of projects.
For example, there might be a material that’s significantly greener and a bit more expensive — enough so that a large scale project couldn’t justify the economic costs (i.e. it wouldn’t be a general purpose replacement for PVC), but such that a small project hobbyist would prefer to have that melting in their garage shop instead of PVC.