Your entire block might switch to zero waste and would likely see no reduction in their property taxes (any reduction would probably simply reduce the local government's deficit).
Where is this true? In every jurisdiction I've ever lived in trash service has been private and I've had to pay for it myself. The service fee is based on volume of trash container. I've always had direct feedback on trash disposal costs.
Probably the biggest externality here is the environmental cost of producing all the single use plastic containers in the first place, but the landfill itself will have externalities too.
Eventually, the rate of semi-permanent waste creation by humans on Earth will have to equilibrate with the rate at which semi-permanent waste is absorbed by the environment. Otherwise, the amount of waste would continue to increase indefinitely. We can certainly go a very long time at our current rate of waste creation, which is why the costs to future-people isn't included in the price. But those costs are real, and potentially include making sure chemical leeching doesn't occur over hundreds or thousands of years, not just decades.
Such as? As I mentioned, landfills are already regulated to prevent leeching harmful byproducts into the environment and many of the harmful things produced by landfills that do escape, e.g. methane, isn't really specific to the landfill itself.
Nah. If this was what was going on we’d expect to see a lot more substitutions, offsets, and so on.
Instead the focus seems to be on personal virtue vis-a-vis the environment and particularly public demonstrations of personal virtue, rather than in maximizing effectiveness.
For example, why is residential rooftop solar being built out in the Pacific Northwest?
This is probably because the social / environmental cost of leaving all the trash you create in a landfill forever is an externality - you don't pay for it with your milk cartons and individually plastic wrapped potatoes. One way of thinking about the environmentalist movement is that it's an individualistic effort to price in one's own externalities, since American society more broadly is unable or unwilling to do this.
Of course broadly these efforts aren't going to solve the waste problem - if they could, manufacturers would not have the incentive to sell products this way - but there will always be a niche market for this sort of thing.