Rancher has been around a long time and isn't cloud-specific. Until this distro can prove itself useful outside of the AWS ecosystem, then Rancher will still dominate.
> RancherOS 1.x is currently in a maintain-only-as-essential mode. That is to say, it is no longer being actively maintained at a code level other than addressing critical or security fixes.
quoting support.rancher.com, taken from the 4th comment down in the linked Github issue