That's not really the case. It's simply a really hard problem and that's easiest to address early on (recycle somewhat right) than to try and filter useful things out of shredded sludge.
It's a really hard problem that big companies show no signs of helping to solve because they have no economic interest in doing so. They use whatever packaging helps their short-term profits without consideration of long-term environmental damage.
It's a typical externalities problem - the full cost of using some types of packaging is not paid by the one doing the packaging.
