Better quality flannel does not pill or pills only in certain colors. It is soft, and warm and it's ok if it doesn't last as long. My sister's flannel backed scrap quilt is only now just wearing out after 8 years, and used year around. It's been washed in the washing machine and put in the dryer on the average of twice a month. I tied this quilt, so I can clip all the ties and reback it, but 8 years is really a good time for something to last. My quilt, completed and tied at the same time, will probably last another 10 since it is only washed twice each year and put away in the summer.
I do have a couple of flannel quilts (once bed sized, a couple couch sized) that are flannel on both sides. Neither shows any pilling after some years of light use. But, both had high end quilt shop flannel. The baby quilt I made for my cousin's daughter only pills in one of the colors and that is minimal. She's 9 now and it gets regular use, although less washing today than when she was a toddler.