Initially, the developers planned to provide Drupal 8 with a bunch of newfangled features. But they were tested and finalized to be added to the 9th version eventually. In particular, we are talking about the capabilities such as:
Thorough accessibility. You can stop worrying about whether your Drupal 9-based site will be sufficiently available to disabled users and users with a low-speed Internet connection. Just breathe out, everything has become much more comfortable to grasp as a whole. Being fully consistent with international accessibility standards and policies, Drupal 9 now has user satisfaction-boosting features, such as:
- improved default contrasts;
- optimized logical tabbing (using the tab key to navigate the site);
- inline form errors convenient to read for the disabled;
- optimized keyboard-only controls.
On top of that, optimized themes, advanced cache modules, and auto-disabling of unnecessary modules makes Drupal 9 perform great even in the conditions of low bandwidth.