Word allows you to adjust the indentation on numbered lists so that the text in a paragraph is flush with the left margin. In Word 365 there are at least two ways to do this:
1. View -> Show -> [check Ruler] -> [Adjust the indentation on the ruler]
2. Layout -> Paragraph -> [click lower right arrow] Paragraph Settings -> Indentation -> change Special from (hanging) to (none), or change the "By:" value to 0
So the author's motivating example doesn't seem to be a particularly fair criticism of Word.