This is a good question and an honest question. My first response is that we as individuals and as nations should never make decisions based on cynicism and futility. This would lead to throwing caution to the wind and living lives of wastefulness. Our waste does not only end up in landfills; it ends up in the ocean as well where animals are now dying at an increasing rate because they mistake our trash for food. https://www.livescience.com/62743-pilot-whale-dies...
Landfills are a necessity. They must be monitored so that they are following the strictest rules to prevent groundwater contamination.
The packaging of so many of the things we purchase is a complete waste of resources and strains our ability to dispose of them.
Plastic grocery bags are trashing our environment and killing innocent animals. I kayak the riverways all across the US. I see the tattered bags hanging from the branches of trees lining the rivers. After the water levels recede following the spring rains and snowmelt, the bags are left in the branches of the trees. Is the convenience of how we transport our groceries more important than being good caretakers of the natural world?
Yes, it matters.