I do not know much about burning plastic, but is it really zero drawbacks to do so? Intuition tells me harmful chemicals would be released. Is it that the burning would be contained and the air filtered?
Correct. The atoms are the same, just in a different order. Although you may occasionally get chlorine which is not in oil, but it's not common in plastic (other than PVC).
>> Intuition tells me harmful chemicals would be released. Is it that the burning would be contained and the air filtered?
No need for much filtering, you just need proper incinerator that provides enough air. You will need to filter out chlorine, but that's so reactive it's very easy to filter.
The harmful chemicals from burning plastic are caused by incomplete combustion.
The vast vast majority of plastic is just carbon, oxygen, and hydrogen. Burn them fully and there's nothing harmful emitted.