I think that we are currenly in the rapid growth phase of price discovery of the cryptocurrencies. It is much more likely that during this period, your earnings from buying and holding cryptocurrencies would outpace your earnings from mining. Mining requires a large initial investment that would pay a profit over time. But, the rate of growth of that profit would not likely match the rate of growth of the price discovery of cryptocurrencies until that rate of growth stabilizes at a much lower rate per annum. That being said, both are near certain profitable endeavors.