Why is the Book of Enoch canonical in the Ethiopian church?

The Book of Enoch is canonical in the Ethiopian church because the Ethiopian Orthodox Tewahedo Church has always kept it as scripture within its broad biblical canon, never treating it as an outsider text. This church holds the widest Christian canon, traditionally numbered at 81 books, and within it Henok (1 Enoch) stands as full canonical scripture that is read and revered, just as it has been for well over a millennium (Ethiopian Canon - 1 Enoch in the Ethiopian Canon: Scripture, not apocrypha).

Every complete copy of the work survives in Ge'ez precisely because this one tradition never stopped regarding it as scripture. While other Jewish and Western Christian canons left it out, the Ethiopian Orthodox Tewahedo Church retained both 1 Enoch and Jubilees as integral to the Bible, so the book is not lost or banned there but simply part of sacred scripture (Canon & Reception - Canon and reception of the Book of Enoch; Ethiopian Canon - 1 Enoch in the Ethiopian Canon).

In this framing the text remains living canon rather than apocrypha, preserved and honored through the church's continuous liturgical and doctrinal life (Book Overview - The Book of Enoch (overview); About - About the Enoch Archive: The Texts).