Anyone who needs to change the font or text display properties to read the content will benefit from this guideline. This includes people with low vision who use a bigger font, and people with dyslexia, reading, or other cognitive disabilities, who may have specific spacing requirements.
Examples
✗ Bad example: Non responsive interface.
The effect of changing the text spacing and line height on a non-responsive interface: some of the headline text of each item no longer displays
✓ Good example: Responsive interface.
The effect of changing the text spacing and line height on a responsive interface: the headline text of each item always displays
(Source: Knowbility article on text spacing)