If we're talking about chemical consequences of alkanes vs carboxylic acids, yes. However, the parent topic is talking about the effect of burning plastics, for

If we're talking about chemical consequences of alkanes vs carboxylic acids, yes. However, the parent topic is talking about the effect of burning plastics, for which consideration it can be thought of as burning fat in that it (as opposed to other plastics where the byproduct cannot be compared to just burning fat.