Most plastic will never be recycled – and the manufacturers couldn’t care less

As long as the plastic is actually thrown into a landfill, it's probably not actually that bad. There's plenty of room for landfills, honestly; this stuff can be shredded, compacts well, and if the landfill is built with proper barriers and modern design there's no reason to expect anything leeching into the water table. If the virtue of people having sorted their garbage is maintained by burying separated plastic apart from other materials, what we're actually doing is pre-seeding potential future fuel stock for some process that can cleanly use the plastic. After all, it burns, so there's energy there... we just need a way to get to it without releasing a ton of gross smoke.

The real problem is when plastic is thrown into the ocean. Rivers of garbage in India are a terrifying sight, and absolutely need to end. The problem here is that plastic is the artifact of a more advanced society, and it rests on certain requirements in order to not be a nightmare. One of those requirements is functioning waste management system, which in turn stems from the civilizational technology of caring about where your waste goes. I assume that that develops in turn as an evolutionary advantage after repeated plagues stemming from lack of hygiene, but this evolution has not happened uniformly to all human cultures.

Significant improvement is necessary. Either waste management, or super-quickly biodegradable cheap organic polymer alternatives. Until that happens, probably it is the case that some countries simply shouldn't be using plastic at all, and should return to more traditional distribution and packaging mechanisms.