Cryptocurrencies will continue to grow. The problem is that no one knows how much they will grow and when it happens. Therefore now it is very promising to build a mining farms.
Not only cryptocurrencies are growing in price, but also the complexity of the network, to produce this cryptocurrency is becoming more difficult, mining cryptocurrency is still profitable, but will have to constantly increase the technical capacity to be in a good profit.
One thing is clear for sure that the mining of crypto-currencies brings income, how much this income is high, this is another question.