It's not a failure because Bitcoin tanked (relatively), it's a failure because Bitcoin tanking was and will always be a significant risk. People who got rich from Bitcoin weren't savvy, they won the lottery. It's not a sound investment decision based on outcome. Investments are sound based on probability and risk beforehand.
El Salvador gambled which is stupid. Whether they won or lost at the lottery is inconsequential to its stupidity.
El Salvador gambled which is stupid. Whether they won or lost at the lottery is inconsequential to its stupidity.