Biodegradable plastic is a misnomer, it just breaks down into microplastic particles and we all know those are a huge problem already.

They hedge in this article by saying "...breaks down into its original components when exposed to salt. Those components can then be further processed by naturally occurring bacteria..." but notice they don't mention which bacteria or how common it is.

Works great in a lab I'm sure but without gathering all this stuff up and intentionally feeding it to vats of bacteria it's just more microplastic junk in the soil and oceans.