In reply to RichJ634:
I find the first thing to wear out on most products is the zip.
Having a sewing machine, I usually just sew a new zip onto the old one, seal the seams/stitching and put a proper old style velcroed flap over the zip if needed.
Had no option but to buy waterproofs with "waterproof " zips recently, when they go, will probably get the same treatment.
Have ME not gone away from relying totally on a waterproof zip on their newer top end mountain gear?
Worth trying a puller if you can source them, but the teeth and puller will both be worn ( out ) to some extent.