I don't think that cryptocurrency is the fastest way to get rich, because the market is unstable and there is a high level of volatility as well. But I believe you can make a good additional income by working with cryptocurrencies in many ways, it is already helping so many poor and unemployed people around the world to earn their living.
I agree with the second part of your statement but the unstability of the market isnt why people might not get rich. Its because so many crappy projects out there are riding the blockchain wave without really contributing anything to the world