I used to make nearly all my clothes, especially for important events. I taught all levels of sewing at the college level -- pattern drafting, wearable art, etc. I think getting a good fit is the main reason people don't make clothes. It requires a good understanding of where the problems are, and how to adjust them for a good fit. It may seem advanced, but pattern drafting gives you that understanding. If you could find a class in pattern drafting, that would actually be a short cut to getting the understanding you need.
Other reasons people don't make their own clothes include cheaper prices and changes in lifestyle and clothing needs. I feel lucky that I got to teach what I did, but times and needs have changed.
I got involved in quilting through making wearable art, when quilting techniques were being incorporated. -- lots of fun and new techniques to learn. That led to art quilting, and I'm still fascinated by it.