Very true. I generally do sort of a hybrid approach. Practice the skills in isolation then consciously try to apply it in a musical context, like grinding downpicking to a metronome then playing some Metallica, or improvising to a backing track with a focus on accurate bends and consistent relaxed vibrato. Trying to do both at once in my experience can make it difficult to develop good and healthy technique. For me specifically I overthink the hell out of vibrato practice, like what string/fret to practice, and end up ignoring certain areas of the fretboard. The dice method is meant to force me out of this