I think you could make an argument that even burning plastic in a firepit vs sending it to a landfill are roughly equal. Climate change and air pollution are both major issues, but so is plastic waste and microplastics working their way into everything. I have no idea of the overall harm of burning plastic is less than throwing it away; they both pollute the environment. I can see the the logic in thinking burning is a viable alternative.

Ideally, though, people would just stop using disposable plastic. Plastic is a fantastic material, but it was never supposed to be for “use once and discard” items. For creating durable objects with a decent lifetime, sure, use plastic. Don’t use it as wrapping over another plastic object.