Because any serious comparison of recycling and landfill has reduced carbon emmisions as one of the benefits of recycling (and similarly burning for heat/power, which is still better than landfill on most grids today).

So, if climate chamge is an issue you care about, then recycling is one of the fixes and landfill and its methane production and waste of useful materials is one of the causes.

But since we live in a world where even the existence of climate change is a political hot potato, I guess I shouldn't be surprised to see one of the fixes attacked with well funded lies as well.