A term used to describe someone who knows a lot about many things, but, with the second tag "master of none" added it transforms into a derogatory phrase meant to emphasize how mastery of one skill is important for deeper knowledge.
However, one, oft forgotten tag is the third one: "is oftentimes better than a master of one". Instantly, the term reverses meaning, symbolizing how a person who knows a lot about many things that integrates their skills allows them to surpass even a master of one.