Have you ever heard of gold? That didn't continuously lose value. I'm sorry to hear you believe the nonsense modern economists, bankers and politicians tell you.

What is "value" here?

If you value being able to purchase a specific good X, and they stop making it, then you now don't have currency capable of buying it. Doesn't matter what kind of currency it is.

If you're using value in dollar value, that asset has the price behavior it does because we live in a stable economy with central banks, 2% inflation targeting and so on. You haven't seen the alternative because you'd be on the street.

What you want is TIPS bonds.