How can currency be ideal if it is decentralized, bitcoin will never get the ideal currency because it is not a controlled by the government and it is its selling point. Imagine a scenario where it is not centralized then countries could just simply take an action by banning the usage of it in their domain, so no, decentralization is not good if bitcoin become an ideal currency.

That thing is I disagree with that, if you want a fast transaction wouldn't it be the same as physical transacction, I think what is needed that an ideal currency is somethig that can't be duplicated for illegal use, tampered with, can leave audit trails if in case stolen and secure.

I think that there is no problem with that, what we need are more secure wallets or focusing more on the innovation of technology towards security.