That’s definitely part of it, but the lb dates way back to before there was any conception of difference between weight and mass. Nowadays, the kg, and thus the U.S. lb, is defined in terms of universal constants (the Planck constant and the speed of light), but traditionally the lb would have been defined by some sort of standard physical object, whereas the kg was defined as the mass of a litre of water. There was an implicit reliance on the force of earths gravity in the measure of the lb, which wasn’t part of the measure of the mass of a kg. So, I think historically speaking it’s understandable to think of the lb as a unit of weight, not mass.
Murdering cultists and monsters while traveling through time, all while trying to save reality from the void. Hopefully the Hague will give me a pass on all the murder, even if it doesn’t exist in my timeline.