It does seem like such a big pain, I agree totally! I NEVER used to pre-wash my fabrics, until I was tested for chemical allergens and the ONE thing they found that I am highly allergic to is the formaldehyde found in the processing of fabric! What a pain!
The whole experience starts when I go shopping for fabric. About 15 minutes in the LQS sets me into a sore throat and itchy hands....and that is if I barely fondle the fabrics! When I find fabric, I have to put it on the cutting table and leave it there so that I don't have to carry it around. About 30 minutes into the shopping "experience" the inside of my hands are scratched from my fingernails and I have almost no voice left! Quite a sight to see actually!!!
When I get the little pretties all home, then I trim the corners back to help with the fraying and wash them with warm water and "free" detergent and a smidgen of "free" softner, and an extra rinse. Then, the second washing is with no soaps or softners. They get to be in the dryer or on the line for a short time, long enough to be almost dry. Then, ruler folded and put away.
When it comes time to use the fabric, then I press it and cut away! But, while cutting and sewing it together, I still suffer the itchy hands, but a lot less than I would without washing them!
I never suffered with any of this in the first 6 years of quilting until I was diagnosed. I don;t suffer too much at home in the sewing room unless I am handling the fabrics. I have well over 2,000 yards in my sewing room and don't suffer like in a QS. The reason is that when I found out, I had to wash all the fabric I owned at the time (just under 800 yards). After putting it back into my room and washing all fabric before it gets into the sewing room, it has removed most of the chemicals. When I enter an LQS, I am surrounded by unwashed fabrics, so my body reacts.
Now, since I have started prewashing, my quilts don't suffer as much shrinkage!