because chart is basics thing someone who wants to understand trading have to understand first.
Knowing charts without having a strategy is still a failure, what is most important in trading are the strategies that you are using, but knowing chart, understanding it is very good, while indicators are very important to predict what the market could be in some minutes, hours or days to come. Charts are not hard to understand, but not having the right strategy could be what a trader can suffer from, leading to more losses than profit.
Chart is basic no doubt but it works directly with indicators. Therefore to understand your chart it means you have an understanding of the indicators that you are using to analyse the chart, so it can be easy or not easy but trading isn't easy if you have not taken care of the emotions. Life trading and practice or mere flipping through of trading history are not the same. If you don't understand your strategy then you can't analyse your chart with the indicators.