Balayage works best on someone who wants their colour to grow out gracefully rather than sharply — because you do not want to be back in the chair every four weeks, or because you would rather your colour looked like it belonged to you than like it had been applied.
It suits most natural bases, but the starting point changes the result. Dark hair takes more lifting to reach a cool blonde and may need more than one session to get there safely. Previously coloured hair — especially hair with box dye or old highlights on it — behaves differently from virgin hair, and that has to be assessed before anything is mixed.
Fine hair, thick hair, straight, wavy, curly — all take balayage. The placement changes, not the technique.