Whether content is easier on the eyes depends also on environmental lighting and monitor brightness/type. For some setups large areas of light content is more f

Whether content is easier on the eyes depends also on environmental lighting and monitor brightness/type. For some setups large areas of light content is more fatiguing on eyes, especially with poorer eyesight and when body text is overwhelmed by whitespace, so it can literally make reading more difficult and likely to even get ignored/bounced (speaking from my own experience). Browsers have thankfully accommodated for such subjective preferences even without site theme choices though via reader modes and userstyles (whether browser or user-forced).