How do you decide who to go to when buying goods and services? Sometimes its obvious because there is only one or two choices, or its habit to go to one supplier or brand loyalty perhaps. Now there is nothing wrong with the proverbial "jack of all trades" but the cliché that they are "Masters of None" must have some foundation in truth. For example, a GP is ok for most medical issues, but sometimes a specialist is needed.

Equally so ...