Why is using spreadsheet to create charts easier than creating by hand?

Answer 1

It is faster. It is more accurate. You have the source data available to you. The chart responds to changes in values and automatically changes. It is simple to put in titles, labels, legends etc. onto the chart. You don't need to do any calculations yourself to create the chart in a spreadsheet. For these and many other reasons, it is easier to use a spreadsheet than doing a chart by hand.