We're writing apps for mostly local government users, almost all of who use IE11 because it continues to have Java Applet support.
Some of these Applet-based things have been migrated to modern web, but many still haven't, since it is almost 15+ years of software development now needing to be re-written.
There have been discussions about Edge's "IE Mode" but unfortunately that only applies to domain joined machines, and they have a BYOD policy.