This super-thorough examination of
aria-describedby is well worth a read.
aria-describedbyis an important tool to help provide information where it might otherwise be missed. However, the attribute should rarely be the sole manner in which information is communicated, as doing so will exclude people not using screen readers from the descriptive content. The best way to use
aria-describedbyis as an alternate way to provide quick access to descriptions that are accessible by other means.