I think the biggest advantage to classical artskills like sculpting and drawing, is that they are faster to achieve the desired effect. If a director thinks a shot may be better with a 360 degree pan of a room, the modeler needs to have the roome modeled and then animate the pan, while the 2D artist, can pop out a rough 360 pan in ten minutes, half hour tops, with far more detail than the quick 3D one could have. Same with a head rotation. when desinging a character. you can really help you modeling if you can draw 32 drawings of you head and make it rotate. all very important and efficient skills. Need to show a director what a jungle setting may feel like or show that you are dapable of doing that kind of project for them, I can do a tarzan style charcoal rendering of a jungle in 3 Hours tops. Course it helps to have a Tarzan Layout artist for your Background and Layout instructor.
YOu can work with out 2D, but why limit yourself. Look at the art of monsters inc book. Thats what makes their movie still standout compared to Ice age. The Artistic planning that goes in before the modeling starts makes a huge difference. To get a job at pixar you are far better off with some classical skills, especially for deign or animation, they prefer artists who can animate classical ove rthose with only 3D experience, they’ll even train a 2D artist over an okay 3D artist with no 2D experience.
I’ll admit there are exceptions, I have seen amazing work come out of some artists that don’t draw, and all I can think to myself is “have you ever sat down with a pencil??? Imagine what you could do”
And if you are doing character annimation or modeling, drawing alone is not enough find a gallery or studio, or even school that has life drawing, life drawing is the most important artskill. If you understand hman anatomy you can draw pretty much anything.
Glenn Keane still goes to lifedrawing sessions so don’t anyone say it ain’t important unless you have smoethng better than him to show for.