How often do you use them? I‘ve used mine frequently from Autumn to spring for ten years. I bet a pair of Dunlops or Hunters bought today wouldn’t last that long.
Not that often, just when the garden is very wet, as at the moment, but they were well-worn up to my acquiring them. They are still perfectly waterproof. I also have a pair of company issued wellies, like new, but they are not so comfortable to wear - not easy to put on, and tight on my calves.