Manual analysis does not keep up with the speed of the market
Anyone who evaluates positions based on charts, news and experience makes decisions with a delay, which costs capital in volatile market phases. Every additional minute of analysis time moves the entry or exit point. In addition, human attention cannot be scaled arbitrarily - the ability to react noticeably decreases overnight, at the weekend or when observing several instruments in parallel.
The result is rarely a single major error, but rather a series of small delays and misjudgments that add up over time.