It is easier for developer but risky for end user. Docker runs as root and you have to trust application developer to use latest security patches for all dependencies.
Simply using the "USER <uid/uname>" directory means you run as non-root user with a specified UID. Kubernetes recommends doing that as a baseline security measure. You can also drop caps from a container so even if you are root inside, you can't do a lot of things root can.
