The user interface and content of digital services must prioritize clarity and inclusivity to ensure cognitive accessibility for a diverse audience. Despite the availability of accessibility guidelines, many websites remain difficult to navigate and understand for individuals with cognitive challenges. This study examines the usage of the World Wide Web Consortium (W3C) Cognitive Accessibility Guidance to evaluate cognitive accessibility and identify common design barriers. Using expert evaluation of ten Finnish websites across the education, business, and nonprofit sectors, this research highlights key cognitive accessibility challenges based on the guidance. The findings reveal gaps in the practical application of cognitive accessibility standards and highlight the need for simplified, context-specific guidance for web developers and content creators.