So, they do this because it's cheaper, if they had to break open all the packaging, they would NEVER get it done.
And looking at their SCALE, it's industrial, which means it must be LEGAL.
You have Financial motivation, AND Legality.
Now you ask Pig feed producer # 2, how do you compete with Pig feed producer #1 that's allowed to use unsorted Garbage.
Well, now pig feed producer # 2 will start using garbage.
Then This becomes standard industry practice. Bad money drives out Good money.
And on the consumer end, How do you know which pig you're getting, plastic pollution pig or corn pig. Because differentiation is virtually impossible, No distinction can be marketed/ made.