As somebody who is a hobbyist at best, this is my biggest sticking point. Anybody can learn to slam together some pixel art in Paint, and even doing more advanced work in Photoshop is not out of reach with a little time and practice. But learning a 3D modeling tool is orders of magnitude harder - I've made a couple runs at Blender and older versions of 3D Max, and there's just so much to making meshes that look decent, and then you have to skin them. And then there is the question of adding animations. My hat is off to people who have developed those skills.
My only hope is that technology to make this process easier will advance. I've seen some demos of people using their phone cameras to scan real objects and generate 3D models, but even if that worked perfectly, it appears to me that there would be a lot of work to process that into passable 3D art assets.