In what top percentile of people who do something do you need to belong to be considered as a master at it? Top 1%? 10%? 25%? The smaller was your answer, the more people who do that thing can’t be a master at it. Among them, that will be the thing many do best so barring a few quirks in statistics, they won’t be a master at anything else, either.
Today’s English has this idiom, jack of all trades, master of none, to describe someone who can do many things without being good at any of them. It’s an idiom I absolutely despise because it makes huge assumptions in its judgment that says more about the stupidity of its creator than how accurate that judgment might be. There are many people who aren’t masters in what they do best, making them also masters of none, but with fewer trades to their name than the jack of all trades. Also, the jack of all trades who has learned to do many things is bound to have put that learning capacity to good use in at least one thing to be pretty good at it, likely better than most of the people doing it. This makes them more a master of at least one trade compared to many jacks of one or few trades.
Logic aside, my dislike for the jack of all trades, master of none idiom is personal, for reasons of identity. I am a jack of all trades, and I’m quite good at some by the stats and recognition, so I don’t appreciate the blind brush off from the idiotic idiom! I was a top 4% distance runner for times. I am a top 1% marathoner for count. I have national poetry awards. I have academic accolades galore. I have earned very well in most professions I’ve done, etc. If none of those could count for being a master at it, then many jacks of few trades are masters of none is definitely true!