A slow website makes someone wait before they can even understand what you offer. On a phone with an uneven connection, that delay is even more noticeable.
Image weight
Large photographs are often the main source of page weight. Prepare them for the size at which they are actually shown and use modern formats. A project image can look sharp without being enormous.
Question every script
Every extra tool can add loading time. Animation, live chat and tracking should provide enough value to justify their cost.
A stable experience
Speed is more than a score. Content should appear quickly, elements should not jump around while loading, and buttons should respond promptly.
Measure real pages on mobile. The results will help you prioritize changes that genuinely improve the experience.