When text is small, extra line spacing is important because it makes it a lot easier for your eyes to find the next line when the text wraps.
But as text gets larger, your eyes don’t need as much help — lineheight of 1 is perfectly fine.
The further your eyes have to jump horizontally to read the next line, the easier it is to lose your place — narrow content can use a shorter line-height like 1.5, but wide content might need a line-height as tall as 2.
