I find it makes my life easier, personally, because I can set up and tear down environments I’m playing with easily.
As for your user & permissions concern, are you aware that docker these days can be configured to map “root” in the container to a different user? Personally I prefer to use podman though, which doesn’t have that problem to begin with
The satellite uplinks these devices use is very bandwidth limited, and quite expensive. I can assure you that it’s not routinely sending anything without telling you.