YouTube had discontinued its annotations editor on May 2nd, 2017, and now it will also stop showing any existing annotations on January 15th, 2019. The company says the adoption of end screens and cards has grown, the use of annotations has decreased by over 70%.
This means you can no longer add new or edit existing annotations, only delete them. Existing annotations still show when using a desktop computer. Annotations were launched in 2008 and were immediately put to use by YouTube entertainers for recommending new videos.
In 2016, YouTube launched end screens as a new interface for linking to videos and sites at the end of a video without any workarounds that included annotations. The site also added cards, a tidier, less obtrusive pop-up option for mid-video text. This marked the end of annotations to up to 70% by early 2017 leading it to discontinue the annotations editor that spring.
Google also mentioned that it will stop showing existing annotations to viewers starting January 15, 2019, and all existing annotations will be removed.