Everything looks like a nail if you are a hammer and all that.
We also shouldn't forget that the vast majority of politicians today are lawyers by education. To whatever degree your assumption holds, it is true of the status quo today as well. Even in that case, having a more diverse set of "masters of one" would be an improvement.
For the US, 32% of the house and 47% of the senate holds a law degree.
Unfortunately, eventually one of the people selected for being less capable get to be at the top and continue the whole play again, getting rid of anyone that is not less capable than themselves.
This is one disadvantage democracies have over monarchies, for a king can surround himself with more capable people all he wants as they are not direct competitors.