You can get Open JDK from any of the following places on them intarweb tubes, and they don't seem to fracture the ecosystem. Linux is available from many places, it may seem fractured, yet Linux seems to be taking over the world. Even Microsoft now "loves" Linux.
https://aws.amazon.com/fr/corretto/ https://github.com/corretto
https://adoptopenjdk.net/ https://github.com/AdoptOpenJDK
https://github.com/ojdkbuild/ojdkbuild
http://www.azul.com/downloads/zulu/
https://developers.redhat.com/products/openjdk/download/