The only thing that matters is if it’s biodegradable. If the plastic won’t break down naturally, it doesn’t matter if it’s made from starch or crude oil.
Polylactic acid is a low weight semi-crystalline bioplastic used in agriculture, medicine, packaging and textile. Polylactic acid is one of the most widely used biopolymers, accounting for 33% of all bioplastics produced in 2021. Although biodegradable in vivo, polylactic acid is not completely degradable under natural environmental conditions, notably under aquatic conditions. Polylactic acid disintegrates into microplastics faster than petroleum-based plastics and may pose severe threats to the exposed biota.
The only thing that matters is if it’s biodegradable. If the plastic won’t break down naturally, it doesn’t matter if it’s made from starch or crude oil.
https://link.springer.com/article/10.1007/s10311-023-01564-8