Docker became popular because of a ubiquitous CLI. Having good UX is only part of the battle: the massive network effect (and associated tooling boost/community support) is significant and should not be discounted.
I'm sure there are similar things to Docker's all-in-one UX that have emerged on the BSDs. I'm also sure there are programs to configure Dropbox using an SCM and FTP links in a fast, seamless way on par with the Dropbox setup flow, but they aren't going to take off, because the predecessor is not only convenient, but is also pre-existing with massive popularity.
The same is true for Docker:containers. Some competitor may replace them in time, but whoever they are, "as good as" is not going to be their value prop.
Docker became popular because of a ubiquitous CLI. Having good UX is only part of the battle: the massive network effect (and associated tooling boost/community support) is significant and should not be discounted.
I'm sure there are similar things to Docker's all-in-one UX that have emerged on the BSDs. I'm also sure there are programs to configure Dropbox using an SCM and FTP links in a fast, seamless way on par with the Dropbox setup flow, but they aren't going to take off, because the predecessor is not only convenient, but is also pre-existing with massive popularity.
The same is true for Docker:containers. Some competitor may replace them in time, but whoever they are, "as good as" is not going to be their value prop.