Saying that fiat money is some kind of a bubble is not a right thing, because in fact it is not. That bubble would have been popped years ago, and as we can see, it still holds for now.
If you have a short-term perspective, I can understand why this seems plausible. But have you looked at a table of all the state-issued monies in modern history? Among the tiny portion of long-term surviving ones (including the dollar, sterling, some currencies that became part of the euro, etc.) the loss of purchasing power over the decades is still staggering.
And these survivors just happen to be countries with a lot of power to make other countries help prop up their money. Interesting, isn't it?
The problem with state-issued currency is that the politicians and bankers have the incentives to degrade and destabilize their own system by issuing or borrowing too much.
The regular cash is something that too many people rely on, to think that there is any chance (for now) that we will have something different instead of paper money.
This is unfortunately true, but is due to the use of state power to maintain what is effectively a rigged capital market. (See my post 'Dissecting the Parasitocracy'.)
That said, after the final failure of the gold standard in 1971, we can finally hope to gain by buying and holding gold for the long term. Of course, the elites and their economists will want us to believe otherwise, by suppressing the price of gold (see books 'The Gold Cartel' and 'Gold Wars.') But the dollar has lost 97% of its value against gold since gold was 'demonetized' in 1971. Bitcoin is arguably in the same boat, as a store of value if not as trading money.
After all, what do you want to see as a replacement for fiat, do you have any suggestions?
If you're asking what an ideal system would be, it would be money and debt that is totally free of state intervention. Depending on the nature of growth in the economy, we can't say what form it will take. The important thing is that the free market should decide. With state money, all the problems of socialism will occur, even though most people don't understand them, since they're financial in nature and are hidden inside the 'capitalist' system.
If you are wondering that bitcoin has any chance to overcome the fiat, then you are wrong. Blockchain network is not ready at all to maintain under such a massive traffic, and the another issue is that the fees currently are exceeding the reasonable amount of money spend for commison. You cannot buy some cheap things ( e.g matchsticks or cans with drinks ) because the price would increase dramatically, because of a insanely high fee payed on every transaction.
Bitcoin, especially at today's cheap price compared to gold (when comparing similar proportions of total supply,) is an arguably superior investment, partly because the elites want to dilute the demand for gold by having investors go into Bitcoin. There are other good reasons.