Even if Bitcoin's price collapses by 50% or 80%, there will be those who trust it as an investment asset, or the currency's value will increase over time, so confidence in it will not be lost.
Bitcoin's price rise of an average of 13% over this long term is not an indicator of confidence; the price has actually risen much higher.
It is still seen as an investment asset by 98% of people, but if it were used as a currency, no one would have to worry about how much its price increased or decreased.