People shit on it but there's a lot of good open-source tooling that supports it.

There are nist l1 profiles

Tutorials and guides for everything

etc

Part of being a good sysadmin is knowing when not to reinvent the wheel. Ubuntu has a lot of options for vetted, hardened, "other people's wheels."

Also, for posterity, the competent ones are running the headless, server version of Ubuntu. (As opposed to the bloated mess that is Ubuntu Desktop). The server version catches a lot of flack it doesn't deserve.