Bitcoin has never failed technically, although some consider that its fall in value is a sign of stalled sustainability. The fact is that they never realized that the reason for the decline was only due to external factors (most of which were due to the policies and conditions of centralized financial institutions), not an innate failure.
Your first statement sums up everything. Bitcoin on its own has never failed and as far as I can see, it never will. It's way better than fiat because it's a currency that when its value falls, there is every possibility that it will go back up, it could take weeks, months, or years but it will get back up. The value of $10,000 in 2010 is higher that the value of $10,000 today due to inflation. Whereas in the case of bitcoin, it's the other way around. 10btc today is higher than 10btc in 2013.
Even now that the market is not in a good place there is still hope and expectations that it will go back up sometime in the future and might even pass beat its ATH, I can't say the same about any fiat currency with the rate at which inflation is eating away at everything,