That's hardly true and is all just perception. In both CG and practical that weight is all achieved via artistry and is not inherent. For instance, take spaceship scenes shot with models, that weight you see/feel isn't because it's a physical model, it's all in the camera work because the model is typically fixed in place and it's the camera that moves and makes it seem like that the model is moving. In CG ,it's the exactly same, it's all in your camera movements that will lend the feeling of weight to your shot. And if you're talking puppets, it's the skill of the puppeteer that makes the puppet seem rea; and not the puppet itself which typically weighs a fraction of what it would weight if it were a living being. This is esp. true in any scene in The Mandalorian where an actor picks up Grogu, even though it's a physical puppet the way the actors pick it up make it readily apparent that it's a puppet weighing only a few pounds as opposed to a living being that should weigh at least twice as much.