User testing is critical during software development as it provides invaluable feedback on user experience and functionality. Involving real users helps identify issues early in the development cycle, allowing developers to make necessary adjustments before the final launch. This process mitigates the risk of costly mistakes and enhances user satisfaction by ensuring the software meets actual user needs. Effective user testing can reveal insights on usability, performance, and potential enhancements, resulting in a more polished product that aligns better with market demands.