Very much so. The longer the line, the more your eyes move and the easier it is to lose track of where you are. It can be worse when you move to the next line, as you lose your frame of reference from the previous line on the other side of the screen.

For horizontal space, it tends to be really hard to design for larger widths and still maintain focus on the main content in a readable way. For example, you should avoid super wide blocks of text as it’s really easy to get lost as you read. This is why you often see a max width with large gutters for wide displays, especially on pages with a singular focus, such as an article.