Manual Trading does take time. The trader needs to perform research, be there to place their orders and spend time reviewing their trades and individual behaviour to try and reach superior performance. Some of these tasks can be semi-automated though. Many traders often let their emotions get to them and start to 'gamble.' It is up to the trader to maintain discipline in risk management at all times, making sure they don't risk too much to allow for losing trades, making sure they trade consistently to allow a statistical edge to work in their favour and making sure they focus on their processes rather than all the noise of other people's opinions.
Many manual traders struggle with being solely accountable for their trading account and will often blame their strategy, or their platform, or their broker, rather than look internally at their behaviour and decision-making abilities.