Test flakiness, particularly in end-to-end testing, is a significant challenge in the development process due to its cost and complexity, often leading to "alarm fatigue" among QA and development teams. The text discusses the issue of test retries masking underlying problems, such as false positives, and emphasizes the importance of addressing these rather than relying on hope for successful outcomes. A detailed example is provided where a simple accessibility test using the cypress-axe plugin uncovers a false positive due to an improper heading hierarchy, which was discovered by accident. The walkthrough explains how Replay DevTools can be used to retroactively inspect test failures, thereby revealing hidden issues such as accessibility violations caused by elements like a missing modal window. This tool allows testers to compare multiple test attempts, identify problematic elements, and ensure that all accessibility checks are properly conducted, ultimately highlighting how flakiness can signal legitimate issues within an application.