Combustion with energy recovery is slightly lower down the "Waste hierarchy" than recycling. Nordics get even more bonus points if they use the waste heat for district heating after generating electricity but I think it still comes out as a bit worse than recycling overall.

There's complicated interactions though, removing the plastics can affect the makeup of the fuel and the post combustion products can free recyclable metal from other materials they were combined with. Recycling processes often have an unrecyclable fraction which can be burned etc.