I guess I'm in the minority because I do occasionally use CAD for sewing projects. I have modified and re-sized clothing patterns, and used CAD to optimize layout of pattern pieces to minimize waste when cutting them out. It lets me check that arm hole circumferences match the length of sleeve pieces, etc.
Having said that, I don't think CAD is a necessary skill for most or maybe any projects. A lot of gear is made from pretty simply shaped pieces that can be sketched up with pencil and paper ; )
Check this out:https://www.youtube.com/watch?v=-6b7HNTttxw