Oh it’s way different. I’ve had to pass a free-hand drawing exam in order to enroll into arch school. I’ve graduated since. I’ve been doing 3d for 10 years, but i can’t sketch anything unless it’s deconstructive architecture. This is not exactly something that you can learn, you can practice a lot and get better at it, but you need to be born with a talent. It’s somewhat similar with 3d, since you do need to understand space. But then again it’s much easier.
A 3d model of a building always goes towards one point - a perfect representation of what’s been put into line drawings, or for that matter, even something that’s in the architects head. It can be either right, or wrong, there is no 3rd outcome. It can be efficient or inefficient in terms of how many hours did it take one person to achieve the very same result. There are a few tricks as to knowing how to achieve something like a soft edge, will it be a chamfer, a fillet or vray-edge, but that can all be either learned or figured out, or just picked up on a forum like this. It doesnt take a whole lot of practice or intelligence to do it, unless people kept their secrets for themselves.