I agree you need to use it daily but disagree that an Ubuntu desktop provides any real insight.

Here's some BASIC questions an ubuntu user might never encounter:

Which processes are currently hogging the CPU?

Which ports are currently open?

How do you setup a remote git repo and/or add a user for limited ssh?

How do you increase an existing swap part without locking the CPU during write at peak loads?

How do you exclude/include packages from being autoupdated on apt update?

How do you ensure opaque crontabs aren't silently failing?

My advice: Setup a Linux server on aws or whatever for a paying customer with medium load. Only the stress of respondong to actual downtime will teach you anything useful.