I've been Prime member of Amazon for .... Well, I'm not sure. Several years. Even though the cost of membership has gone up (next raise will make it double of what I started at), it's still worth it for me. Even as a teenager, I detested shopping, and that has not changed. In addition, the closest mall is 45 minutes away. Between my time, my dislike of shopping, and gasoline, I'd much rather pay for the membership and have purchases delivered to my door.
I would definitely contact Amazon to report fabric that was not acceptable after washing. I try to post review on Amazon when I get exceptional customer service or product - but I will also post if there is an issue that isn't resolved. If the issue is resolved after a sub-par review, I edit the review to reflect that.
What I miss about fabric.com prior to the purchase by Amazon is that they used to have good sales, both in price per yard and percentage off purchase sales. If there is something that I have seen and am interested in, I would look online and compare prices, as I would for any merchandise. Then I'd decide if I wanted it badly enough to order or not. If I'm not getting it on sale, the answer to that is "Meh" more and more often. Getting older, retired, and have. So. Much. Stuff. But if I needed it ("need" being subjective!), I'd order.