Is the reason why 3D animation varies so much because of the artist’s skill, or is it the sophistication of the technology?

Still trying to determine why it seems 3D computer animation varies so much. I wonder if it is solely on the skill of the renderer, or how sophisticated the program they are using is. Some 3D animation has parts that I find impressive. Such as this one with the piano, the shadows look believable and the reflected surfaces good, but the people remind me of Gumby.

In this playground feature, the hair looks more like plastic as do most other items to me, though the shadows are decent. The hair starts to become more real looking with this gal, but still rather lifeless. This woman had hair I can believe in, movement and texture wise, certainly miles in front of the two kids with the X-ray box. Is the animation with the two boys and the X-ray box just a cheaper program, or was it the inexperience of the artist/renderer? Is it a little bit of both, if you have a less sophisticated program and a novice renderer you have plastic looking hair and Gumby Claymation-like textures? And why do many of the features have that generic all-the-same look?