Most UX problems are invisible until they show up in the numbers
The interface looks clean. The design system is consistent. The screens feel professional. But people still drop off before they convert, sign up, or understand what the product does. That is usually a UX problem — not a visual one.
The hierarchy is wrong, so the visitor processes information in the wrong order. The flow has too many steps, or the steps do not build confidence. The page looks calm but says nothing that resolves the visitor's real question. These problems compound silently. They rarely announce themselves as UX failures — they just look like underperformance.