Redesigning will not fix the issue when the problem is traffic quality, keyword targeting, conversion path architecture, or messaging clarity rather than visual design or technical infrastructure. If the site has a traffic problem, a redesign will not generate more visitors and, if executed incorrectly, may reduce traffic.
Before beginning any redesign, the first question should be whether it is truly necessary, and if so, why. Without knowing the specific problem, there is no way to know if a redesign will solve it, and even if it does, the same outcome may have been achievable faster and cheaper through targeted changes. A slow site with a 60% bounce rate has a structural performance issue, not a branding problem; changing colors or adding interactive elements will not fix a technically outdated foundation. Similarly, a better design will not save a broken information architecture, and a new CMS will not fix unclear messaging. If qualified leads are not converting after a redesign, the keywords may be misaligned or conversion paths may be broken, problems that survive any visual refresh.