It is not difficult in 2022 to build a web site that is accessible - most web page authorship software automatically creates pages that are potentially WCAG-compliant and there are plenty of software tools that will detect features that violate the guidelines. Then why are so many web pages less than fully accessible.
Write a 2-3 page paper that seeks to explain why web page creators still fail to follow WCAG and other guidelines. It will include the perceived barriers to accessibility or the perception that creating inaccessible web pages has no consequences.