It's closed source on the server side, proprietary, and has various issues. I was pretty shocked when they forced it into a LTS release, and the implementation

It's closed source on the server side, proprietary, and has various issues. I was pretty shocked when they forced it into a LTS release, and the implementation was not optional and was terrible. They handles upgrades poorly, polluted the mount space, required manually cleanup, and destroyed boottimes. If you want containers, why would you go with a proprietary canonical technology instead of one of the better open source solutions? After all isn't one of the main promises of containers increased compatibility? Even the ubuntu derivatives are switching away from snap.