Many really old quilts were tied with wool yarn, over the years the yard would become like a button as it felted with washing and use.
I used embroidery floss (DMC brand) to tie the first quilt I ever made, 30+ years ago. I have had to redo some of the ties over the years, but it has held up. I just used cheap lofty poly batting. I did not know any better at the time. I had to whip stitch it together, but it too has help up to use.
I do not worry about a quilt wearing out. I make quilts to be used and enjoyed, not saved as an heirloom. I do not make bed quilts, I make picnic quilts, lap quilts, cuddle quilts, baby quilts, wheelchair quilts etc. Quilts that will see use, wear and tear. Oh, I also make quilts for pets. It is a great way to use up practice quilts.