I must admit that the reason I so respect the competent all-around general practitioner is that personally, I am confessedly incapable of doing all things well.
I limit my practice to criminal law. That's all I do. Period. Full-time.
I don't represent folks in divorces. I don't draw wills or draft contracts. I don't form the occasional corporation or sue on behalf of those who suffer personal injuries.
My practice runs "from traffic to treason", with the heaviest emphasis being the defense of the person accused of D.U.I.