The article highlights the dangers of bypassing built-in sanitization in JavaScript front-end frameworks like Vue.js, React, and Angular. It showcases the vulnerabilities in Firefly III, a finance application that uses Vue.js, where attackers exploited a combination of Client-Side Path Traversal and Sanitization Bypass to inject malicious HTML code into the error_message variable. The article emphasizes the importance of verifying that inserted content is safe and not controllable by malicious users. It also notes that other unrelated issues in the application can lead to XSS vulnerabilities, making it crucial for developers to ensure proper sanitization and security measures.