TV budget, folks. They could just use the existing high end model from the movies for Hulk, She Hulk has to be created from scratch. Has there been any other similar shows with a large shapeshiftiing character? What effects did they use? And how did it look?And yet Mark Ruffalo is only 58, not exactly bulked, and he did a convincing job playing an 82 character.
If your benchmark is Hobbiton, that won't be met, because this production is nowhere near that scale. And the automatic assumption that practical = better is very suspect.