> a lot of crypto bros have marketed it more as a casino than a solution to a decentralized currency.

Another way of looking at this is that the main players have a vested interest in keep it as a casino. Therefore it'll never become a currency, because casinos and monetary systems have fundamentally different requirements when it comes to stability.

Instability in cryptocurrency is a feature. It'll never go away unless it gets regulated to the point that all the things that differentiate it from the fiat monetary system are gone.