Accessibility is hard. It's not just a technical problem. It informs every stage of conceptualizing, designing, and implementing a web site. Accessibility is end-to-end.
For instance WCAG 2.1 requires a minmum text color contrast ratio of 4.5:1. If a web designer and other stakeholders haven't taken this on board there's a risk they'll select an inaccessible color palette. And that's just one requirement.
Designs that appeal to management and other stakeholders are more often hostile to accessibility than not.