Crumpled linen is acceptable beach-casual style. Pressed linen is more polished, looks deliberately chosen rather than 'fallen out of laundry'. Five minutes pressing makes the same garment look £100 more expensive.
How to press linen well
Iron damp. Steam setting. Press cloth between iron and delicate areas. Hang on hanger immediately after to prevent re-creasing. Spray bottle for quick touch-up on the day.
Where this matters most
Linen trousers, shirts, dresses for office or smart events. Casual contexts unpressed is fine.
Two minutes per garment with iron. Significant visible difference in finished look. Worth it for any linen piece you bought to look refined.