Angular 10 officially released deprecating support for Internet Explorer 9 and 10; Read more about the changes - Themesberg Blog
Angular 10 has been officially released and some of the most notable changes are deprecating support for Internet Explorer 9, 10 and mobile. Read more about the changes in this blog post.
themesberg.com
The poor souls who has to support IE are not running Angular 9, do not want to upgrade Angularjs (Angular 5 at best), they don't even want to touch that "working" code base.