Drupal, accessibility and WCAG - Rolf Meijer

Legislation with regard to accessibility and usablilty for website is extended in the coming years. Drupal has not only the ambition to support WCAG 2.1 AA, but also quite a good reputation when it comes down to accessibility and usability. There is usability research done, form the community there is a specialised Accessibility-team, specific documentation about the subject is is published on the drupal.org-website and in the issue queue tags can be added for accessibility and WCAG issues, even per guideline. But how well does Drupal perform out-of-the-box with regard to accessibility and WCAG?