Forex is more about fundamentals (economic indicators, political and economic news) for long term trends and trading. For short term technical analysis can give you good insights if you take its signals under the context of long-term fundamentals. That said, if you learn to read the price action well you can get good FX gains. With cryptocurrencies, the problem is that it is a relatively small market with little volume that can be moved easily by the "whales". In addition, a simple news can cause savage market oscillations that can cause huge losses if you are on the wrong side.