Accessibility goes beyond usability, emphasizing the need for content to be usable and accessible to all, promoting equality and inclusion on the web. Further insights on web accessibility can be gleaned from this video by Frank Spillers.
Accessibility is crucial in web design because it ensures websites are usable by everyone, including people with disabilities. It improves usability, expands your audience, boosts SEO rankings, and helps you comply with legal requirements.
Building a Fully Accessible Responsive Component (End-to-End Example). To understand how responsiveness and accessibility work together in practice, lets build a reusable accessible card component that adapts to screen size and supports keyboard and screen reader users.

Accessibility boosts product quality. The last argument is more for your teams, than stakeholders: when people build accessible websites, they often care a lot about quality, from code to usable design. This means, that, you can talk about the following metrics, to help convince people
Accessibility, usability, and inclusion are closely related aspects in creating a web that works for everyone. Their goals, approaches, and guidelines overlap significantly.

Furthermore, visual representations like the one above help us fully grasp the concept of High Rise Building Accessibility And Usability.
How To Build Skyscrapers? Modern Technology & Construction Process Of High Rise Building0:24. Deep foundations of the Dubai Creek Tower2:08.