I'd say it depends. Amager Bakke in Denmark is a combined heat and power plant that burns waste and emits 687 grams of CO2 per kWh vs natural gas at 290 to 930 grams per kwh and coal at 900 to 1,050 grams per kwh. This makes burning trash CO2 competitive with Natural Gas. Using it for district heating probably improves the picture here because resistive electrical heating on a standard grid emits more CO2 than natural gas heat or pumped district heating.

It plausible that in cold climates burning trash has significant advantages.