Bookmarked:
accessibility.uxdesign.cc 
This “candid and practical handbook for designers”, penned by Sheri Byrne-Haber is a refreshingly broad and actionable take on advocating for the accessibility mindset for practitioners in digital design, with valuable impulses for managers as well.
It starts out with rebuffing the usual personas of “accessibility critics” to be found in teams and organizations, e.g. “The people who want to see ‘the business case” or “the people who believe ‘well, it only impacts a small number of users’”, and summarizes: “Everything that makes accessibility difficult ties back to one root cause: People not giving a damn about others who are different.”
Next, it encourages designers to not aim for perfect accessibility but make an effort:
Your first attempt at making anything accessibly will be awful. Don’t use this as an excuse. Even awful is better than 98% of what other people are doing.
Perfect accessibility, as the guide book states, is something that is almost impossible to achieve. Accessibility practice is more about “moving the needle forward” and “opening yourself up to criticism” than to churn out products that are literally accessible to every single human being: “Commitment is the key. Just start.”
Yet, the final chapter of the booklet then moves from this encouragement – that any attempt at accessibility is better than none (and even small efforts, unfortunately, lift products to the top of that list) – to a call for striving for “great” instead of “good”. It’s a holistic view on accessibility, where empathy trumps compliance, where the focus is on the overall experience instead of the product alone, where feedback loops are in place rather than purely relying on up-front research, where design systems formalize accessibility, where accessibility is taken beyond the #a11y circles and put in front of design audiences.
This is a great intro to accessibility on a non-technical level and could be a powerful intro text for design students and managers alike. Having been involved in some strategic work around accessibility maturity in organizations lately, I recognize a lot of the managerial impulses from this text – getting inclusive design thinking rooted deeply indeed takes a lot more than educating the technical experts; it’s the management and design departments where true change needs to be achieved.