The shocking experience of having the handle of a can opener break off while partway through opening a can early one morning was enough to prompt the immediate purchase of this old and obviously much-used can opener at a church sale when I came across it: there was nothing to break!
(I forget exactly how I dealt with that early morning predicament; I seem to recall a knife and prying and being thankful the can was of pineapple slices that could be encouraged to slip through the narrow opening: chunky pineapple would not have complied) 
Not sure exactly how to use this ‘new-to-me’ opener (it might even be older than I am!) I was prepared to get out a hammer, but – the pointy piece pierced the can easily. And somehow the hand knew how to sort of lever it around the can; talk about ancient knowing.
In a surprisingly short time I had the lid unfastened.
Now, I did note that the inside of the can is not smooth like with a more modern opener so the jagged edges could be problematic for curious critters and I washed it out more thoroughly than usual and squashed it flatter so it wouldn’t be attractive. And it won’t do for cans intended to make a telephone with two cans and a string. But I do like the simplicity, the cleanablility, the old-fashioned’ness.