When it falls apart faster by handling than by being alone.
Sometimes all you can do with a well loved quilt is to use it as batting and put it inside a new quilt. I've done that often with worn out baby quilts.
There are all sorts of things you can do to rescue a quilt from minor repairs to covering the entire project with illusion bridal netting and but ultimately cotton decays. I rather like it how quilts change with age, sometimes fabrics don't fade evenly and a whole new design/color sense comes out at the end.
My quilts do typically get a couple of years as dog quilts before they are completely discarded.