Docker Hub is the de facto standard Docker registry, literally, if you don't specify a registry when pulling an image Docker will invisibly prepend docker.io/ to it. That bit is fair enough really, it's their software and their registry platform so why not prefer it? From the beginning of the Linuxserver project we used Docker Hub as our primary registry; as we grew we started mirroring our images to Gitlab and Quay.io, more as a backup than anything else, there was no reason for us to have conc...