Okay, so I know the reason the physics in Breath of the Wild and Tears of the Kingdom have so many weird exceptions and edge cases is because the games' designers are concerned foremost with puzzle-crafting, and only secondarily with producing a coherent world model, and nearly every bit of weirdness can be explained by the fact that some puzzle mechanic required the games' physics to work that way. There's simply no deeper unifying logic to be found, and trying to find it is a good way to give yourself a headache.
One of those pieces of weirdness lies in the relative weights of various objects, particularly in relation to Link, the player character. Some objects are incongruously heavy or light for their size because the puzzles in which they appear require them to be, and Link himself is weirdly lightweight, presumably because that was the easiest way to cause him to experience the exaggerated knockback that many puzzles require without making the forces involved ridiculously strong.
Most objects and characters which recur among the two games are at least consistent in this respect. However, it has been empirically determined that in Breath of the Wild, Link weighs the same as 8.5 apples, whereas in Tears of the Kingdom he weighs the same as 10 apples, and now I can't stop myself from wondering what fucking puzzle mechanic required Link to be exactly 1.5 apples heavier.
